Refinishing is about more than just making a car look new again—it’s also a matter of safety. The look is all the more important today as self-driving vehicles drive demand for radar-compliant paint.

What Is Radar-Compliant Paint?

Rather than referring to specific standards, radar-compliant paint is a general term for coatings that don’t interfere with radar. What that looks like can vary between makes and models, as different cars use varying radar technologies.

The need for radar-friendly coatings stems from the growing number of self-driving features in today’s vehicles. Autonomous cars use radar to navigate in the dark when vision systems may fail or as an accompaniment to other sensors. Adaptive cruise control and blindside warnings sometimes use the technology, too.

Unlike cameras, radar solutions often reside behind painted surfaces, which is why special coatings are needed. Many paints reflect radio waves, and if enough reflection happens before the signal can leave or get back to the sensor, it will limit the radar’s accuracy.

Potential Issues With Non-Radar-Compliant Paint

Failing to account for radar signal integrity when refinishing cars with advanced driver assistance systems (ADAS) can cause several problems. In many cases, these issues have significant safety implications.

Transmission Interference

The most common problem you may run into with radar systems is that many automotive coatings interfere with radio signals. Metal particles in polychromatic paints account for much of this interference, thanks to their electrical conductivity.

Studies find that the more metal pigments in a paint, the more it interferes with radar accuracy. At the same time, a higher metal content is often popular among customers, as it makes finishes shinier. Shop owners who aren’t aware of this problem could easily refinish a radar-housing part as they would a conventional car, unknowingly blocking the radar system.

Blending coat layers on top of radar parts could similarly interrupt radio signals. An overly thick substrate can produce similar problems.

Overcoating

Radar compliance can also be an issue of paint volume, not just the type of coating. Some finishes may not produce much interference in a single layer, but adding multiple coats amplifies their signal-blocking effect. Consequently, overcoating can turn an otherwise radar-compliant job into a safety hazard.

Some ADAS can see through one or two layers, but not more. The depth to which they can penetrate may also vary between different substrates and metal contents.

What constitutes overcoating will vary between OEMs. Some justify recoating, others say radar-housing parts can take just one refinishing job, while still others prefer to avoid fresh paint coats entirely.

Non-Repaintable Parts

Along the same lines, some OEMs may advise against refinishing their radar-housing components at all. BMW, for example, says not to paint damaged sensors but to order a replacement part in the specific color needed instead.

Standards like this ensure a refinishing job matches the color of the original vehicle while providing certainty that the radar will function correctly. Manufacturers like BMW may not trust independent shops to use the correct kind of paint or to apply it in a thin enough layer. Given the potential impact on driver safety, they see an entire replacement as the safest option.

How to Ensure Your Shop Is Radar Compliant

As ADAS becomes more common, demand for radar-compliant paint will rise. Consequently, the time is now to make sure your shop can handle jobs involving radar systems. Here are some key steps to follow to meet these needs.

Stock Radar-Compliant Paint

The first and most straightforward measure is to ensure you have radar-compliant paint on hand. While the line for radar-friendly coatings may vary between OEMs, you can look for a few common characteristics.

Metallic flakes are the biggest thing to look out for, as over 60% of automotive paints contain them, and these can interfere with radio waves. Look for coatings with relatively low metal concentrations, especially aluminum or silver. Toners like pearl and titanium-based mixtures can also affect radar, but generally to a lesser degree.

Some paint companies have started to release coating branded as radar-friendly, and these are the safest options. Where no such labels are available, look for those with solid toners and relatively thin substrates.

Create a Formal Process for Radar-Friendly Refinishing

Your shop also needs a specific process for handling ADAS refinishing jobs. Selecting an appropriate paint is an important first step, but workflow considerations are also necessary because the application can impact whether the coating interferes with the radar signal.

Train all employees to use thin coatings and avoid mixing when repainting radar-housing components. Similarly, everyone in the shop should know how to recognize ADAS so they don’t overlook these sensitive systems while refinishing.

Ensuring paint cleanliness is also important. Air from most screw compressors will contain roughly three parts per million of oil, which is acceptable for most cases, but ADAS jobs may require fewer contaminants. Using activated carbon filters in your air compressor will keep that figure lower.

Refer to OEM Manuals Before Refinishing

Part of your formal radar-compliant painting process should be to refer to the OEM manual for the vehicle in question. Some ADAS don’t use radar at all, while others have radar of varying strength or sensitivity, so a model-specific approach is crucial.

As the self-driving sector matures, the industry may become more standardized. Until then, though, paint and repair shops must go by each manufacturer’s latest guidance to know how — if at all — to approach refinishing a radar-housing component.

Remember that OEM manuals update often. Look online for the latest versions for each vehicle and stay up to date with any changes from major manufacturers.

Set Expectations With Customers

Finally, you should keep customers informed about radar-specific refinishing requirements. The extra care such systems require may incur higher costs. Similarly, some manufacturers will recommend replacements, which could be more expensive and time-consuming. Communicating these factors upfront is key to maintaining loyalty.

Up to 60% of consumers today say that trust and transparency are the most important characteristics for a business to have. Being upfront about potential cost increases or service delays builds such a relationship.

As a rising number of people drive cars with ADAS, conversations like these will become increasingly common. Still, drivers may not know that their vehicles have unique needs. Discussing it with them before performing any service is essential in light of this discrepancy.

Self-Driving Cars Introduce New Paint Considerations

Autonomous features will not only change the way traffic works — they are also reshaping repair and refinishing workflows. Auto shops must learn of these considerations to provide reliable, safe services to all customers.

Fully self-driving vehicles may be a ways away from being a reality, but many models already have radar sensors. Learning to work around these systems today is key to remaining successful tomorrow.