I just got mine 4 weeks ago today. I have learned a TON by reading this site.
1st, read all the stickies, if not enough to find solutions, enough to find what common problems are.
There is a factory cup holder in the center console (unless it has been removed and replaced with a plastic bin)
They are fragile to close, and the trick is to lightly pinch the silver top and black piece together, and there is zero effort to close.
There are several nice ideas about mounting additional cup holders, I like the ones that people put on the bulkhead.
The RCM (Relay control module) is known to fail due to 3 bad solder joints, not just on the Crossfire, but other Mercedes as well.
Other known issues are Crank position sensors, and thoroughly funky security/theft/ignition key systems.