on my golf i have the normal 3 dials etc for the heaters like most cars, however there is a top of the range model which has digital controls with other bits as well, has anyone ever done a similar type swap and if so how hard is it? i assume i need to change the complete heater assembly, matrix etc ? if i got all the wiring / heater and controls could it all be easily wacked in and connected up or i it not that simple?