I had a Cellet holster for my 8120. I removed the belt clip and glued it to my car mount. Very clean.
I can't seem to locate a holster that will hold the 8900 with the screen facing out so I can replicate the arrangement I had with the 8120.
All of the car mounts I've found have been way too bulky.
The Cellet Holster for the 81XX Cellet Blackberry Pearl 8100 Black Rubberized Elite Holster
They make one for the Bold. So, maybe it’s just a matter of time.