I know your on about the B5 but on the B6 it says in the handbook that the car will not warm up quickly on Idle. (15 mins Idle time is the same as 6-7 mins driving time,,,, in my opinion as long as you dont high rev it when you start it, give it chance for the oil to run around and set off 5 - 10 seconds later... then take it easy util the engine is upto running temp...
thats my opinion anyway..
Cheers