My stat was broke so I have had another fitted today (OE) Now it gets up to temp perfect and all my issue are gone no more flat spots no more cold running engine and the MPG has gone through the roof, gentle run round town 47mpg cant be happier.. When I put my heaters on VAGCOM says it goes down to 70 degrees. If I put it on half strength on the heaters it doesn't change.. Is there some sort of regulator for the heater matrix itself? Some sort of thermostat for the heating? it went from 90-70 in around 2.5 minutes which shocked the lad doing the data logging. and couldn't find the issue himself. Any ideas?