One problem related to automatic transmission control module has been reported for the 2003 Volkswagen New Beetle Convertible. The most recently reported issues are listed below.
2003 vw beetle, transmission control module . . . Original owner, regular servicing,completed. Automatic 6 speed sport shift. Runs fine when the car is cold. Drive 10 miles or so an the car starts to jerk and fails to shift into 4th gear. Yesterday got stuck in 3rd gear while on hwy, created a danger for me and others on the road. Took it to a trany place, not the transmission, but suggests it is the transmission control module, which is located under the dash on passenger side. When the car fails to shift the rpms go to 5k or 6k then the car jerks and tires screech, I called vw and the parts guy said that a new trany runs7 k or so and he is aware of the problem as I described it above.