Similar thing happened to me about two weeks ago.
The car was parked and when I went back out to the car there was a Rover 25 disgracefully parked infront of my car about 2 feet from the kirb and it was parked at a stupid angle too.
I checked my front bumper and, whadda ya know!! scuffs on the corner.
I left a note with two ten pence pieces inside saying the following.
"here's 10p towards your driving test cos you obvoiusly haven't had it yet, and here's another 10p towards rear parking sensors cos you obviously f*cking need them you TW*T!!!!!"
About 1/2 hour later I got a phone call from my sister saying that an OAP had just spent 10-15 mins trying to get into the car before even trying to drive. I felt guilty for all of about 3 seconds as a realised that if somebody is that bad at driving no matter who they are.....THEY SHOULDN'T BE ON THE ROAD IN THE FIRST PLACE
rant over!