I bought the above mount and cant say it is perfect. The mount has a solid built and can rotate as well. However, the camera and power key are inaccessible. I have setup shortcutd with proximity sensor to access the home screen.

I had no intentions of using the supplied car charger since i have the fantastic Nokia DC-10 charger. However, dont even try using that charger because the edges of the usb end are not rounded. Infact the usb male end seems a little bit bigger that the DC-10 charger. So in all possibility it might break the usb port of N900.

Btw, the car mount wouldnt hold the device with the otterbox on it.