One of the most common, if not THE most common, problems associated with trailer towing is engine overheating. With factory installed trailer towing packages, a heavy duty cooling system is usually included. Heavy duty cooling systems are available as optional equipment on most vehicles, with or without a trailer package. If you have one of these extra capacity systems, you shouldn't have any overheating problems. If you have a standard cooling system, without an expansion tank, you'll definitely need to get an aftermarket expansion tank kit, preferably one with at least a 2 quart capacity. These kits are easily installed on the radiator's overflow hose, and come with a pressure cap designed for expansion tanks. Through the dealer parts network, Volkswagen offers cooling and lubrication system modifications designed for towing.