BMW, Nissan and Peugeot dropped their factory support for the last season of the STW.
After his initial four-race streak Abt would only win one additional race while Alzen claimed six, and at the final race the gap was only a few points.
Abt looked to have secured the title running in a strong position in the last race, but on the last lap he was taken out by Opel driver Roland Asch, who had already been black flagged for a previous incident.
This allowed Alzen to claim the championship in a highly controversial fashion.
The title would however be handed to Abt some months later by a DMSB court of appeal.