that is painful
I had two experiences where my bike ended up parked right behind someone's car or truck.
In both cases I was eating lunch and could see my bike - and in both case I somehow 'knew' the person would back into it.
The first was a woman with a car, I watched her go out, and walk past my bike and get in her car. I figured she just walked past the bike so she knows its there. She got in the car, fiddled around with something for 5 minutes, then she called someone on the phone... started the car up, put it in reverse, and I ran out NO NO NO NO NO! and stopped her.
The second time I had parked behind a pickup truck, a good 8 feet back. I saw the guy heading for his truck and before he got there I decided OK Lunch is OVER and ran out and got on my bike.