I have a 350Z Roadster. After 3 1/2 years, the top faded to a pale gray and began tearing around the rear window. the spread everywhere. The local service rep said it was an absolute material defect, and he'd never seen anything like it. He put me in touch with the Nissan Customer Service, who told us that it was out of warranty, and they wouldn't do anything because of "service record", which they never asked for...(I've done all the service the owners manual recommended) Oh yes, there is no service to be performed on the top.
It is disgusting how they handled me--wouldn't let me talk to a supervisor, and just brushed me off.
I put a sign on the car and drove it around.
NEVER BUY A NISSAN CONVERTIBLE.
For pictures and a little more explaination, goto
http://www.nissan-convertibles.com