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Lol Crambo, thanks for making me see the funny side. Wish I could sometimes, but I won't.
The lane is surfaced, so it's not from stones or anything (and the damaged spots too big for stone chips anyway), plus it's such a short, narrow lane (6 houses long) with a sharp bend to get onto it that you can only do a few mph anyway. Also the fact that the damage is only up one side of the car leads me to beleive it's deliberate.
You're right Ice, the lane does belong to the landlord and he keeps telling them to stop parking there and they stop for a week or so, then they start again.
Anyway, I feel better after having a few laughs over it and I've got some primer and touch-up paint so I'll tidy the car up today and see what develops. I'm also definitely going to look into the CCTV idea.