So, I'm buying a new car, agreed price of £34,500. The dealer is offering something called GAP insurance for £465, which will last 4 years. If the car is written off in that 4 year span, then they will top up my insurance payout such that the total is what I originally paid. Good idea? I'm leaning towards getting it, but since I didn't have to decide immediately, I said I'd take advice.