I have had a 2007 roadster since 2008, and the whole car has almost been completely trouble free. A handful of times the canvas top has pulled out of the bow track at the very back where it sits on the trunk. There are small metal clips that hold it in place in the track. If it becomes more of a nuisance I considered bending the clip tips to give them a little more bite in the track to hold it in place. The only other issue with the car was the leaking valve covers which it seems everyone gets.

I've also been a forum member since 2008, and excluding the back windows coming loose on the 2005 models, I don't think there have been a lot of convertible top problems, but they do happen.