Hi, This is my second Z4. My present car is a 2010 Z4 I30s. My first one was a 2003 and before that, I had a 2000 z3. I find 2010 runs great but drives differently than 2003. I am having some trembling with the run-flats which weren't available in 2003. Also, I am finding the hardtop convertible roof will stick either going up or down. Is this a common problem? My car has 74000 miles on it. What I like about this car and all the other 3.0 engines is the wonderful torque and power it produces.