Man, I love this car. Do you have the others in that DTM '92 pack? If so, how do they compare to the bimmer? I have the E30, but on the Touring Classics, and I've tried the DTM Merc, and it's also awesome.
I would just try all of the DTM cars and see if any of them stand out to you. I just drove them all around Zolder for a few laps each and here's a short rundown on what I think. All with the exact same setup, too.
Mercedes: Definitely a wild machine when you get on the power. Slides were controllable for the most part, braking was solid and the car felt good through the turns.
BMW: The M3 is the tamest of the bunch for me. It's very forgiving with the power and the brakes are predictable and rarely lock. I can't really get the M3 to slide unless I really want it to.
Audi: The Audi is great on the power and super planted around turns to the point that it didn't want to break traction at all. However, the brakes were terrible to me. They lock under the slightest of pressure which is terrible on my DFGT pedals.
Mustang: Probably my favorite of the bunch. Sounds the best and controls about equal in power, handling, and braking. It'll get loose but it will follow through with your intended action with a little finesse. Brakes are great and it feels planted through all the turns.
Opel: My least favorite of the bunch. It had the same brake problem as the Audi but without the benefit of being super stable in corners. It didn't like my corrections very much to slides and I felt it was just no fun to drive.