Ok, here is my opinion on stickers:

Stickers are authorized if they are from after market performance parts manufacturers that you actually have purchased parts from and actually utilize the said parts on the car the stickers are placed on. (Sounds all legal and $h!t).

For instance, sporting Eibach stickers on your side passenger windows and all you really have done is ghetto trim your springs is unauthorized use of stickers. Get the point. The said stickers should also be well placed and if colored they should match your ride (if you car is painted hot pink, brown stickers just won’t work). I think stickers are just ads to thieves that state, “Hey local criminals and car thieves! I have all this over priced after market gear on my ride and if you come and steal my car it’ll get you lots of money to buy more crack!” I prefer a “clean” car but that’s just my IMO. I have seen some nice rides with well placed stickers.