The sounds are fine for me, Merceded and Audi sound different and sound fantastic.
One point Id like to mention though. I am doing a ch'ship with Merc, Audi and Alpha only. Theres usually a few drivers that are normally found at the top in real life, and they are languishing down in 20-25 positions all the time, they never seem to exit the pit garage during qualifying. The drivers i notice that tend to do this are Schneider, Spengler, Ekstrom, Tomcyck, Green and one or 2 others. While at the top, there are drivers you dont normally expect to see up there (like ickx, stoddart, luhr, schumacher, margaritis), although no disrespect to those drivers. It just takes the edge off the 'realism' of it.
Again, im finding on some tracks the AI run very wide on corners. Tracks ive found this so far - Barcelona GP, Istanbul, Nurburgring, Oschersleben and Zandvoort. AI is on 89-90%, they're really quick, I cant keep up with them on most tracks lol. Theres also a difference on some tracks, sometimes i can be 2 seconds a lap slower, others, 2 seconds quicker, although im guessing this is down to the track rather than the dtm mod?
The action cam (mercedes particulary) is really odd, it seems like its in the passenger seat and quite low down. The alpha action cam was fine (presumably cos it was taken from the wtcc xtreme cars). Not tried the action cam in the Audi yet.
Still, great fun to drive.
