Personally I don't see the issue if it's something you want to support. But putting them on there as a 'poser' ... no (think the Fast and the Furious). I think it's HILARIOUS when someone tries to be something they're not and fails.
Here's my car ... E90post and VAC Motorsports
In the top center of the back windscreen I have a Helix sticker, though it's hard to see.
