My wife purchased a used '99 beetle gls with the 2.0 L engine. She has had many trips to the dealer about the check engine light that keeps coming on. The dealer says everything checks fine, and is always there with open hands to collect the cash for "turning the light off". We have called VW of America and now have a case number, and again the car is in the shop this week for the same thing. Anything we should look for, or anyone have any suggestions? Thank You.