I just got my 2000 Jetta TDI with 300K on it and love it. I just had the opportunity to try it on the hi-way so I tried the cruise control. When I first engaged it, it would take right off uncontrollably so I shut it down. Later when I tried it, it seemed to work fine except it would act like it was shutting the engine down briefly and regular intervals each 30 seconds. It continued to do this so I shut cruise off again. Any ideas what could be doing this???? Throttle position sensor maybe??? Everything else seems to work just fine when I'm not in Cruise Control Mode.