I'd say I'd be indifferent. I wouldn't be particularly pleased I would have to go out of my way to remove it, but at the same time, there are more important things to get upset over. It's not like I get pissed when I have to pull a flyer from a local business, event, etc. out from under my windshield wiper when my car is parked in a high traffic area. It's simple marketing, I guess. Not to condone it, or promote it, but it's actually a kind of clever little idea they had to place a rear end photo of a GT-R right in the driver's view. If it left any sort of residue after removal, that wouldn't be too cool.
Do you get pissed off when people step foot on your property to innocently place a little something on your front door knob/handle? Is it an invasion of your space, privacy, and property, or just something you shouldn't think twice about, and leave it at face value?