In reply to Jus:
Yes, I know what you mean, I have little sympathy with people who feel like they own the street outside their house, they are only a short step away from those you read about leaving passive-aggressive notes on ambulance windscreens - but there does come a time when it seems like taking the piss.
The car I reported was also not really that much of a problem, just irritating. It was taking up more space than it needed to, and parking is at a bit of a premium here as in so many streets these days. In the end it just went away one day while I was at work, I don't know but imagine the owner either managed to get it going or had it taken away for scrap.
Tricky. I was nowhere near ready to try any of the sort of erm.. 'direct action' that's been suggested here, but there might have come a time, so after I reported it and got nowhere it did occur to me that perhaps I shouldn't have bothered. Mind you, it would be just my luck to try something tricky with a trolley jack and end up getting arrested!