i dont think its a bad idea, i dont think he will get it for free but if some one turns around and says we will bang it out half price thats not a bad deal even if he gets 25% off its still cheaper than full price and they get some proper sponsers stickers than on a budget car looks kooler than just some randon stickers.

bear in mind that knocking the job out half price will prob cost them nothing all it will cost is them no profit on a half a day job.

imo thats very good adverising even if they only get one more customer