As far as I can tell, there are no roof rack systems available for the coupe. Without a roof rack system, you couldn't mount a roof mounted bike rack attachment. You might be able to mount a universal rack, but I tend to stay away from those unless I really don't care much about the car.
You might consider a rear mounted system. A trailer receiver on a coupe might be a bit ugly but would allow a hitch mounted system. Check out our sponsors to see if any might have one. If not, a quick search on the internet should give you some matches. Then you can choose a hitch mounted one. Though most of the hitches I've found require some level or rear bumper trimming.
An interesting find I made was also this product:
http://www.birdautomotive.com/...5.htm
I'd probably try and contact them for more photos as the ones on their site are not very clear, but it could deserve some merit. Uses it's own receiver design and not as universal as a hitch, but may serve your purposes as it carries bikes and skis if you get the proper attachments. The design kind of hybrids between a receiver system and a trunk mounted system. Doesn't look like it requires any cutting or trimming.
Whatever you decide, stay away from cheap designs. I've been looking into the possibility of a bike rack myself as I've been biking lately, and I've heard of many nightmare stories with some of the cheaper racks.