After a winter journey, you wash the grey residue off the doors, but some road dirt remains beneath the car. Underbody washing helps remove salt, mud and contaminants from surfaces accessible from below. At a suitably equipped self-service car wash, you can do this during a normal visit using a lance with a small wheeled trolley.
At TIXE, we have developed two separate programmes: Underbody wash and Underbody protection. The first cleans; the second applies a wax intended to provide temporary protection for washed surfaces. For drivers, it is a convenient way to complement car care. For car wash owners, it is an opportunity to broaden the offering with services whose purpose is especially easy to demonstrate in winter.
Why wash the underbody in winter? Road salt in numbers
During the 2025/2026 winter season, GDDKiA used 468,935 tonnes of salt to maintain its road network. These figures cover roads managed by that authority, not total use on all roads in Poland. They nevertheless show the scale of winter salting. 1
Spray from the wheels carries water, salt and mud towards the floor, wheel arches and components beneath the car. Accumulated dirt can retain moisture. Areas where stones or abrasion have damaged the protective coating require particular attention. Hyundai's manual for model year 2026 lists the build-up of salt, dirt and moisture under the vehicle among the causes of corrosion. 2
That is why winter care should also include the underside of the car. ADAC states that underbody washing can help remove salty dirt that promotes corrosion and support existing corrosion protection. 3
Do new cars need underbody washing too?
Modern cars have factory-applied protective coatings and underbody shields. That does not mean cleaning can be forgotten throughout the car's life.
A good example is the manual for the model year 2024 Volvo V60. The manufacturer describes durable corrosion protection while also identifying regular washing and removal of substances that promote corrosion as part of its care. It also highlights the need to repair stone chips promptly. 4
The car's age is therefore not the only criterion. Its condition, coating damage, operating conditions and manufacturer's recommendations all matter. A car regularly driven on wet, salted roads has different exposure to winter dirt from one used occasionally in dry conditions.
Underbody washing at a self-service car wash — how does the TIXE trolley work?
A conventional lance makes it difficult to direct water conveniently beneath the car. The TIXE solution uses a shaped lance fitted with a small wheeled trolley. You guide it by the handle while standing beside the vehicle. There is no need to lie on a wet floor or raise the car.
The head inserted beneath the car directs jets towards the surfaces above it. Nozzles pointing in different directions help cover a larger area. The programme uses softened water with detergent, supplied at a pressure selected for this application. 6
In practice, you move the trolley gradually beneath successive accessible areas of the underbody. Guide the lance steadily and leave room for the head to move freely. If ground clearance is low or shields are hanging down, do not force it beneath the car.
This ease of use makes it possible to include underbody washing in a normal car wash visit. The driver has a tool designed to work from below and can watch a short video of its operation before starting the programme.
Explore the solution: TIXE underbody washing programmes.
Slide the trolley underneath.
Guide it beneath the car.
The shaped lance lets you work from beside the car. The trolley directs water jets towards accessible underbody surfaces.
The demonstration shows how to operate the equipment. The video's length does not indicate how long it takes to wash the entire car.
See the next stepsHow to wash a car's underbody step by step
Before first use, check the bay instructions and the washing recommendations for your vehicle model. Programme settings and the way it is started depend on the equipment at the specific car wash.
- Position the car so you can access its sides. Check ground clearance, hose position and the space needed to guide the trolley.
- Select the “Underbody washing” programme. Use the lance provided for it. Hold the handle firmly and start the equipment according to the bay instructions.
- Move the trolley steadily. Cover successive accessible areas from below. Do not strike vehicle components with the head or hold the jet in one place for long.
- Finish removing the dirt. The aim is to rinse deposits away, not merely wet them. Rinse and finish the programme according to the car wash instructions.
- After cleaning, select protection if you want to add wax to your care routine. Apply it to washed surfaces using the correct programme and following the bay instructions.
- Put the equipment back and leave carefully. Before joining traffic, check the brakes at low speed in a safe place. Mazda's manual highlights the need to dry wet brakes by braking gently while driving slowly. 5
Pressure washing must take the vehicle's condition into account. Do not direct the jet at close range towards damaged shields, exposed connectors or other parts for which the manufacturer restricts washing. Hyundai's manual identifies rubber and plastic covers and connectors, among others, as parts susceptible to damage from an incorrectly used jet. 2
Watch a longer demonstration of guiding the trolley50 s
Underbody wax protection — the second stage of care
After removing road deposits, you can select Underbody protection. At TIXE, this uses a dedicated ceramic wax applied with the lance and trolley. 6
The programme is intended to leave a wax layer that supports temporary protection of washed underbody surfaces. It complements regular care between washes. During the same visit, the driver can clean accessible surfaces and use an additional protection stage.
The correct sequence remains essential: first wash thoroughly, then apply the product according to the instructions. The layer's durability depends on the car's operating conditions and contact with water, dirt and washing chemicals. We therefore treat wax protection as part of a repeatable care routine.
Remove salt and mud.
Underbody wash removes salt, mud and road dirt from surfaces accessible from below.
Convenient cleaning beneath the car during a car wash visit.
Complement your care routine with wax.
Underbody protection applies a dedicated wax after the surfaces have been cleaned.
An additional stage of temporary protection as part of regular care.
How does this differ from workshop corrosion protection?
Professional underbody treatment in a workshop may include inspection, shield removal, corrosion removal, surface preparation and drying, and the application of selected protective coatings. Its scope depends on the vehicle's condition and the technology used.
The wax programme at a car wash is for routine care of accessible surfaces. It does not remove existing rust or repair gaps in factory protection. Visible corrosion, flaking coatings or damaged shields require a workshop assessment. Likewise, the name “ceramic wax” does not mean a multi-year coating applied through a detailing process.
How often should you wash the underbody, and is it worth doing after winter?
Base the timing on the car's actual dirt level and the manufacturer's instructions. Pay attention to the underbody after a longer journey on salted roads, after driving through mud and at the end of the winter season.
Washing the underbody after winter helps remove residue that may have accumulated during the season. Mazda's manual recommends thoroughly rinsing the underbody and wheel arches after every winter, as well as regular cleaning during use. It emphasises removing accumulated dirt rather than merely wetting it. 5
There is no need to wait until spring if the car is already heavily soiled. Choose conditions in which the bay can be used safely. We explain the principles for freezing weather, vehicle preparation and drying in the guide washing a car in freezing weather — when is it possible, and when is it better to wait?.
Where can you wash a car's underbody?
Look for a car wash with a clearly labelled underbody programme and dedicated equipment. At a self-service car wash, this may be a lance with a trolley, as in the TIXE solution. Underbody washing is also included in some automatic car wash packages — check the scope of the specific programme before paying.
The presence of a conventional high-pressure lance does not mean the bay offers dedicated underbody washing. Similarly, a bodywork waxing programme does not confirm that a separate underbody protection programme is available. The simplest approach is to check the panel labels and the operator's information.
Adding underbody washing and protection to a car wash's offering
For car wash owners, both programmes address a specific need: customers want to care for parts of the car that are difficult to reach with a conventional lance. Offering underbody washing and protection in one place expands the services available during a single visit.
These are complete programmes with separate functions. Give them clear names in the menu, explain their sequence and place brief instructions beside the bay. A video showing how to guide the trolley makes operation quick to understand. Winter messaging can focus on salt and slush; spring messaging on removing residue after the season.
From a business perspective, this offering creates several opportunities:
- An additional choice during a visit. Customers can extend their car wash to include the underbody and its protection.
- A clear way to distinguish the site. A specific bay function is easy to show in a photo, video or information sign.
- More convenient operation for drivers. The dedicated trolley makes the underside of the car easier to reach, while two named programmes make the sequence clear.
- Seasonal messaging based on a need. A reminder about salted roads and washing after winter relates directly to a service available at the bay.
The retrofit scope depends on the existing installation. For car wash upgrades the equipment, water and product supply, programme controls and winter protection arrangements must be selected. TIXE can assess the options for a specific site and propose an appropriate configuration. It is also worth including these programmes when designing a new car wash.
Drivers' questions about underbody washing and protection
How much does underbody washing cost?
The price depends on the specific car wash's price list and how the programme is charged. With time-based charging, the time needed to clean the car also matters. Check the rate at the bay and whether protection is a separate programme. There is no single price across all sites equipped with TIXE technology.
Will the trolley wash the entire underbody, including beneath shields?
The jet cleans surfaces it can reach. Shields, underbody panels and vehicle geometry may limit its reach. Washing at a bay does not include removing shields or cleaning enclosed sections.
Can you apply wax to a dirty underbody?
Carry out protection after washing, according to the programme instructions. First remove deposits, salt and mud. The wax programme does not replace surface cleaning.
Will a car wash protection programme remove rust?
No. The wax protection programme cares for washed surfaces. Existing corrosion and damaged protection require assessment and appropriate treatment in a workshop.
Is underbody washing only needed in winter?
It is also useful after driving through mud and whenever dirt accumulates beneath the car. Time the next wash according to the car's operating conditions and its manufacturer's recommendations. Winter provides a particularly clear reason to highlight this part of car care.
Add underbody washing and protection.
Want to offer drivers convenient underbody cleaning and an additional protection programme? Talk to TIXE about equipping a new car wash or expanding an existing site. We will tailor the solution's scope to your installation and the way you serve customers.
Sources and further reading
- GDDKiA, “Winter 2025/2026 summary”, 2 June 2026. Salt consumption relates to the network maintained by GDDKiA. Open source.
- Hyundai, model year 2026 manual, “Exterior Care”. Sections on underbody care, causes of corrosion and pressure washing restrictions. Open source.
- ADAC, “Dos & Don'ts: Washing a car in winter”, 15 January 2026. Underbody washing as a way to remove salty dirt. Open source.
- Volvo, V60 2024, “Corrosion protection”, updated 28 October 2024. Factory protection and the importance of regular cleaning. Open source.
- Mazda3, 2020 manual, “Underbody Maintenance”. Thorough rinsing after winter, dirt removal and drying the brakes. Open source.
- TIXE, “Washing programmes”, “Underbody” section. Description of the proprietary solution and both programmes. Open manufacturer's description.