I've got the perfect spot. I am a stickler for hiding things like that myslef, so I ran to lowes and picked up a $2 package of velcro, placed one side inside the big door hand on the drivers side (right where your left hand would be). Hard to explain, but it's the fatest part of the door handle that runs Front to Back right at your side. It's a spot that you really never would grab often, if at all. I then put the matching velcro on the opener and married the two. Voila, hidden garage door opener that is at your side at all times. the cool thing is when someone is riding with you, the movement to reach the opener and activate the door is so subtle that they think your new MINI automatically does it for you.
Let me know if it works for you.