Not sure that its just down to jealousy. There are so many threads about car cleaning on the forum that its clear that a lot of 172 / 182 owners are proud of their cars and take a lot of time looking after them.
I think that the chav mentality is more about p*ssing someone else off than about making themselves feel better - any car owner will be p*ssed off if their car is keyed, but someone who clearly spends a lot of time on their car will be more so. Its the reason the scum kick in phone boxes etc - it inconveniences or annoys others, and makes the chav feel that little bit better about his sad, pathetic life.