As Will said, check over the rag top very very very carefully, If its under 5 degrees C it will not operate correctly.
Make sure, you inspect every seam from the inside while a friend passes a torch across the top side, you may notice the fabric splitting, best place to check is where your right ear is when sat in the car, also as Will expressed the rear seam needs very careful inspection, the one above the rear window.
I am led to believe that the motors for the rag top cost circa £700 from nissan, and there are plenty of them, 5 motors if i recall
Dont let me put you off but just go over it with a fine tooth comb.
I have a roadster and love it. The advice given by me/will is from having problems with the rag top material splitting.