This is not just you unfourtunatly.
The whole thing seems to be a rapidly growing problem in the UK and it is one of the main reason I wish to migrate to another country when I'm a little older. As you quite rightly said, so many peoples lives seem to consist of doing nothing but getting drunk all their waking hours and wreaking havoc on normal peoples lives on a daily basis - most of whom work hard for the things they do and buy.
The problem is regardless of the intentions of the person(s) who did this do your pride and joy - they will get away with it, again and again. Infact, even if they did get caught ( which isn't going to happen ) they'd probably get nothing more than a slap on the wrist and a small fine.
If you went up the back of some one in a carpark, chances are you'd have the deceny to leave a business card on their windshield to sort something out. The fact is, good people get used in this country something cronic. I bet most of the motorists on here have all been convicted atleast once for speeding - while this IS a crime, and a potentially serious one - it must annoy many of you that so many shoplifters'/vandals/theifs/rapists and attackers go for months, years or even indefinatly without ever having a slap on the wrist.
Yet, Mr Joe Bloggs taking his hard-earnt car out for a spin, paying his premium car tax, over-priced insurance and dutified petrol, will get convicted for doing 80mph on a empty motorway at 2am.
People moan that this is a nanny state, the irony is most people who live in the state could probably benefit from an actual nanny. I'm sure Englands average IQ is plummeting year on year.
Our family cars ( 3 cars, 1 camper ) have had no less than 4 acts of vandalism on them in the last 18 months. We don't live in a 'bad' area either.
1x wing mirror broken ( on the pavement side! - cost me £140 )
1x roof slashed, radio stolen. £80 radio. £1400 roof and dash replacement. Nice.
1x muppet jumping on the roof of our old company vectra. ( We actually heard, chased, and caught this guy - slap on the wrist by the police who were en-route and caught up with us after rugby tackling the drunk to the ground )
1x driving into the back of my car... small dent and lots of paint chips - still not got it repaired.
Anyway, I do feel for you, very much so. I hope you manage to get this sorted out with minimal problems from the insurance people as well. You really aren't the only person with these issues... I think I speak for many people here when I say everyone is as fed up as you with the additude of what seems to be a quickly growing minority of people.
Best of luck!