Most car makers have now gone down the route of using "clutchless compressors"for fuel and power effiiciency.In simple terms this means the ac pump is driven continuosly whether the ac is on or off.The cooling demand is controlled by en electronic valve within the pump.However these have proved to be not the most reliable of units and Vag have had a large number of failures.If a Golf system is working correctly,then is no reason for it to be any worse than another maker.