Our car has just been damaged in a similar way. A car that was parked next to ours was set alight in an arson attack which then caused damage to ours. As far as I can understand it is suspected that the neighbouring car was attacked by a disgruntled ex employee of the owner after they had been sacked. In our case the car that was set alight was parked illegally on double yellow lines (ours was parked legally). Would this allow us to claim through the other cars insurance? If they were parked legally then our car would not have been damaged.