Panavise Windshield Mount works with n810 mount
 

Although you need 4 nuts and bolts (8x20 seem to work), this panavise mount will attach to the n810 mount:

http://www.shopstormcomputer.com/ssp...pf_id=11029139

googling for "panavise windshield mount" finds many vendors (with the picture in available from google checkout).