I think either of those two pods out by the vent would be great. As far as I know neither is available for our cars yet. That first one is made for the MS6, and is said to not be compatible with the MS3s. The second one is made for right hand drive vehicles, but if there is sufficient interest it may be made available for LHD MS3s.
Well if those options aren't yet available, I may end up going with this one from ProSport:

Or this one from Auto Performance Crossover: http://*************.com/images/Autometer/1pod.jpg
Has anyone had experience with either one? I've seen several people mention they were going to get or had already gotten the ProSport one, but haven't seen anyone say if they liked it or not.