Keep it handy so that when some jackwagon cuts you off on the highway you can wave it frantically at him out the window as you speed past him.
Really I keep it holstered and on my hip. There have been a few times on long trips that I'll remove it and tuck it between my seat and the center console (still holstered).
What to do with gun while driving?nothing! don't text either!
Seriously, though, For short trips of less than a couple hours, it stays on my side. (8:30-9:00 Lefty)
For really long trips, I have a holster mounted in the center console, which provides stability, is secure, and reasonably accessable.
It's a little less accessable for my Right handed wife, but she can still reach it reasonably quickly.
Having a "good" gun belt, IE - made specifically to have the weight of a gun & holster hung off of it, not only does wonders when you're up walking around with the gun - it can also really help keep things where they need to be while seated.
Also - if you carry directly at 3:00 - that's the widest part of your bone structure (note - not widest part of your waist...) But it's the "hard part" of your pelvis and generally not all that great for IWB carry. Try moving the holster backwards behind the point of your hip and see if that helps things while seated.
I bought one of those sticky dash pads and just toss my gun on the dash when I drive, helps to get people out of my way on the highway in the passing lane
I think I might just try holding it out the window. And while I am at it I might just ditch the holster all together and just hold it every where I go that way I always have I ready for when I see those 5 year girls I've been hearing so much about. On a more serious note I think I will try moving it backwards more.