The large sizes of most seats (Cobra, Corbeau, Recaro, OMP, etc.) don't fit well in cars with a tight cabin like ours.
They were even a tight fit in an e34 M5 (not mine), and they'd constantly rub against the B-pillar.
They are a bit more comfortable than the medium & small fitment ones for the more 'well-built' of us though.
Don't forget to factor in the cost of brackets/mounts too - Recaro wanted about £300 for Z4M ones last time I checked.