I have a maxi cosi which I will place in my coupe in a couple of days (after the 27th). I'll let you know how it works out. There are a couple of posts on here about car seats (they are easy to find with the search function). I think the cosi is listed as one that fits. I just happen to have one already. If you find one that fits, please post the results because I am interested.
there is a thread somewhere on this site that discusses this topic. the general consensus is that recaro is the best. mine fits in my GT nicely. i liked it so much i bought two - one for the wife's car one for mine.