A survey of 120 estate agents by used car dealership Network Q, reported here by Reuters (who apparently don't have better things to report), suggests that an old car parked in your driveway can reduce the value of your house by 8% or even prevent viewings. If it's in your neighbour's drive, it can damage the value of your own home by as much as 5.5%. Clearly, there's little science in these figures, but the message is obvious: offer your neighbour a couple of hundred for the wreck, then get it towed to the house you want to buy and adjust your offer accordingly.