Noise from the front latches (BANG! BANG!) is normal.
Rear windows do tend to get creases. When the weather gets HOT again you can park it with the rear facing the sun (south) with the top up, and try it for a few days and it does help some. Eventually a trim shop can replace the windows. They didn't some up with a solution for this problem until the SLK (MB didn't anyways
)
Gilly