doesn't have to be explained to them in a way that is based if they're normies, but find literally any excuse and keep bringing it up under different reasons, like maybe poor hygiene or bad personell. you get my point. this should be one of the most basic things you can do and impact locally
Mechanic fixing your vehicle? Make sure they are a White male.
Seriously, just ensuring whomever is doing any work for you is a White male will ensure superior quality on average and it's significant the difference it makes.