I recently had a similar experience with a local dealership clearly articulating to me that no test drives would be allowed on a used M3 I was interested in. Granted, I pulled up in my own M3, so the seriousness of my interest should not have been questioned.
The arrogance of the dealership really turned me off, and I left. Fast forward a few weeks and I was now interested in ordering a new M3 and for whatever reason I gave this same dealership a chance to earn my business. I was looking to test drive DCT before finalizing my config (had never driven it and wanted to see how much I loved it before plunking down the extra cash for the option) and this same dealership again told me they couldn't accommodate my request.
Another dealership in the area handed me keys to a brand new DCT equipped M3 within five minutes of me walking through the door. Any guesses on which earned my business?