I've recently looked at Aero SS (Auto) and Hammond's old 'Max, but in the end my Aero 8 S3 is too good not to keep and I can add a M3W for a lot less than replacing the Aero 8.
Looking forward to trying to work out what to do colour-wise, and hoping to see more road tests and early versions to steer me in the right direction. Tend to be a bit conservative on colours (Aero 8 is Stingray Grey / Black interior) and expect the seats on the M3W will end up getting stood on quite a bit and getting wet too, so an easy colour like black with a reasonable contrast exterior is where I am right now. Might even go for the same colours on both so Stingray Grey if they'll do it without charging a bundle.