I know this has been said many times before but the Urban Cooling Kit does much more than just cool in heavy traffic. It isn't the most attractive thing but it does do quite a good job of keeping the temperatures within limits and getting some cooling air to the back of the engine when on the move. High temperatures and hot spots will kill your engine. You also get an ECU flash to operate the fan that has the benefit of a better fuel map, all for about £150.