I had to replace my 2007 Z4 convertible top last fall. I have an extended warranty, but the dealer said that because there was water in the motor, it was not covered under the warranty. Apparently there is a little drain hole that allows the water to drain, but sometimes it becomes clogged. Cost was around $1100.00. While I was there another guy came in with the same problem. Is this a common problem on Z4s and why is it not covered on warranty? The clogged drain whole seems to be a design issue that should be covered on warranty. Amy ideas.