If you don't want to get another expensive mount or want to use a case, try the Arkon Mega Grip mount. It's affordable and you can choose a variety of mount options. Here it is with the EVO:
I found out that the car mount has the same connection as Arkon mounts posted above, so if you have the old moto mount and upgraded to a D2 you can buy the Mega Grip holder for $10 and attach it to your old mount. Saves you some $$$.