Totally know where your coming from dude, unfortunatly in this world you can keep nothing good, no matter how much you try its other people with no respect just ruin it.
I always park my car in the furthest place from where I'm going, ie no one parked within 20 spaces of me, come back and 9/10 there will be a car parked 2 feet from me
makes my blood boil.
To most people a car is just a car, a means of getting about and they couldn't care a less about it getting damaged, but they don't consider the other person who's car is their pride and joy
PS I tried the sh!t heap car thing years ago, lasted 2 months and I bought something nice again, life's too short fella enjoy it while you can