This has been happening for several years now, before the movie came out. I wonder how many of them are real Transformer fans and how many just stick TF logos on their car just for the sheer heck of it. At the last school I worked at I had a colleague who drove his son's car to school for a few weeks while his was in service or something, and it had a Decepticon insignia on the bonnet. I asked him if his son was a Transformer fan and he said no. (o_O)

I've actually yet to meet a Transfan who's had a TF logo stenciled onto his/her car. I've had stickers... that's about it.