i was thinking of mounting it the way miata owners do it. check out the pic here:
http://www.seriousauto.com/interior-accessories/cupholder/cupholder.htm
BTW i believe this is the exact same one. i haven't mounted mine yet as i wasn't sure i wanted to do anything permanent. i almost stuck it on top of the swing up armrest but still have not decided.
will someone post a pic of it attached to the door panel?