I had another look at the small review of the Salzburgring destruction derby.
http://www.youtube.com/watch?v=qC952LqI75g
By the looks of it at 1:50 minutes, you can see Wollek's car on a tow truck, so the grey car mentioned earlier must be somebody else - Ludwig Weber perhaps... another one not on the list.
shortly before Wolleks car is Schmitt leaving his M3, so he must have been racing at some point.
So your theory of filling up the vacant spots for the 2nd race with the non-qualifiers from race 1 sounds reasonable. Otherwise it probably would have been a 10-15 car race and this way they had an almost full grid again.
by the way, here are some great videos from the very wet practise sessions at the Salzburgring
http://www.youtube.com/watch?v=qEOjS...8&feature=plcp
http://www.youtube.com/watch?v=8O7VR...9&feature=plcp
and a video in the rainy paddock, showing a whole variety of cars including DTM and STT starters. Also is that Steve Soper at 3:24 ?
http://www.youtube.com/watch?v=GXkQL...1&feature=plcp