One problem related to rear seat belt has been reported for the 1999 Volkswagen GTI. The most recently reported issues are listed below.
The rear center seat belt of my 1999. 5 Volkswagen Gti trapped a passenger in my car. Upon exiting the vehicle, the rear center seat belt locked up and would no longer retract or extend, which left a passenger stuck in my car recently (it was necessary to unbolt the seat belt to free the passenger). The unit is no longer functioning. Based on the information gathered from other Volkswagen golf/gti owners in the 1999-2005 year range, this is a common occurrence and has occurred specifically. I believe this clearly shows product defect and it is a safety concern. I can obtain and submit proof that this has happened in several other golf/gti model vehicles if necessary, there is a very large vw forum online which has several instances of this complaint stretching back several years.