My car is a 99 A4 1.8TQM. Got a check engine light and a code for the coolant temperature sensor over the weekend. I utilized the great info in the tech articles here and some web pages elsewhere. The replacement for mine was a green one like one of the articles. Also replaced the rubber o-ring and plastic clip. The dealer charged me $32 for the sensor. A little steep considering pap-parts.com had it for about $25. Yes, you CAN do it with a vag-com, a great site like this one and a little brain power. :-)