I made up my own custom vent mount bracket for the Axim.
Used a large 'bull dog' clip and 20mm wide adhesive backed velcro.
Cost a few bucks for materials and 10mins of my time.
Email me if you would like picts etc.
Also hooked the audio from the Axim to play through the cars' rear speakers, which significantly improves the sound quality. Another bonus is being able play MP3 files. ...........