Hi! You had some issues with auxilary heater on your Treg (http://www.clubtouareg.com/forums/f93/aux-heater-tdi-252538.html). Did you resolve your problem? I'm having similar issue, that my coolant temperature is not rising at all. I've changed thermostat, but that did not resolve the issue. It's -25c now here in Finland and it is very annoying that car does not warm up at all.