Here are some mistakes to avoid when installing w212 spoiler:

Choosing the Wrong Size or Type of Spoiler: In general, spoilers are made for specific vehicles, and not all spoilers will fit all vehicles. So you want to make sure to choose the right spoiler for your particular make and model of car. Also, consider the purpose of the spoiler (e.g. aerodynamics, appearance) and choose a design that suits your needs.

Vehicle surfaces not cleaned prior to installation: Dirt, dust, and other contaminants can interfere with the adhesives or other fasteners used to attach the spoiler, which can cause the spoiler to bond poorly or even to the vehicle incorrectly.

Spoiler installed too high or too low: The position of the boot spoiler will affect the overall aesthetics of the car. Also, installing the spoiler too high or too low can obstruct the driver's view, which is dangerous.

Irrespective of local regulations: Some regions have laws governing the size and location of spoilers. Always check local regulations before installing a spoiler on your vehicle.

Neglecting to test your spoiler: After installing your spoiler, it's important to test it under different driving conditions to make sure it's working properly. This includes testing at different speeds and in different weather conditions.

Overall, installing a spoiler is a great way to improve your vehicle's performance and aesthetics, but at the same time, make sure it's installed correctly and safely.

Next I will tell you how to install the w212 car spoiler:

The first step is to confirm whether the car spoiler you bought is suitable for your car. You can put the spoiler on the rear of the car first to check if it fits the surface of the car.

The third step is to clean the surface of the vehicle. After the surfaces are cleaned, make sure they are completely dry before installing the trunk spoiler. Wet surfaces may interfere with the glue.

The third part is taped to the back of the fin. Make sure to try to cover as much of the spoiler as possible with double sided tape. Position it properly on the trunk lid and peel off all the double-sided tape covering it in one go. Then press firmly on the rear spoiler to fully secure it to the trunk lid. If you want your spoiler to be held in place more securely, you can use an adhesion promoter on the spoiler before applying the double sided tape.