Throw some emails to VF Engineering. they were looking at my car (space is a bit more than the 3) and said they had a kit that could be modified to work on the 2.3. They have a buttload of BMW projects in the works at this point, so didn't want to start any new projects, but couldn't hurt to throw interest their way if you want. Also, with no form of tuning, there's not much to do as well.
