Completed my 1st road trip in my newly purchased 2000 911C w/ the top down, however when put back in garage the rear windows would not go back up. Looked online in owners manual but no info. The front windows go up/down w/ no problem and the top functions correctly. Also a little black plastic piece in the lock mech. is broken, is this functional or cosmetic? Need help as the car has bugs and dirt and am ashamed to take out now.