Ok, here's something I guess I hadn't thought of before: google: vehicle holster.
Found a couple interesting links. This one:
http://www.buybrownholsters.com/new_products.htm
has an interesting solution. Velcro! Stick one side to the dash and the other side to the back of a flat holster. Pics are towards the bottom of the page.
http://www.holsterusa.com/store/index.p ... evstart=12
http://www.gunbroker.com/Auction/ViewIt ... m=56747448
Thanks to all of you. I feel like I've been floundering with this issue and though it would be silly to bring it up. I guess most other folks are trying different ideas to see what works too.
I've been trying the leg tuck for a few days and seem to be getting comfortable with it. If I'm on the brakes hard enough to make things fly around the car or making a high-G turn, my right leg is usually planted hard enough that the holster isn't moving. I'm a little worried about someone spotting it since I'm sitting in such a low car, but then I'm not doing anything illegal either so I guess I shouldn't worry too much. Besides, someone would have to be looking for it to notice what it is.
I definately didn't want to try just leaving it on the seat next to me. As relaxed and defensive as I drive most of the time, I still like to have a little fun if I find myself on an open freeway ramp. I've watched my cell phone go sliding numerous times, and I don't want to see a gun go floating away from me! And given the situation above where someone threw his bike in front of the car and assaulted the driver, I would think there's a good chance you'd have to hit the brakes quick to avoid the bike, watch your gun go flying to the passenger floorboard, then what good does it do ya when the guy is at your window??
Anyway, thanks again everyone!