I think it would be better idea to clamp the mount to just passenger seat, and not both of them together. It will be strong enough to hold the camera, and you won't have unnecessary movement that drivers seat will create from your weight.

 

good point letmein, I may just do that instead.

 

Thanks!

 

This work really well, thanks Smike! I made one last night and tried some test footage with it. Definitely pretty solid. Though I need to figure out a way to tilt it forward without rolling the seats up. I added neoprene fender washers so they didn't dig into the seats. I also electrical taped the whole thing so it doesn't look so ugly and has no sharp corners. It works incredibly well. I need to do some small adjustments and try out a friends go-pro.

Here's the updated supplies list:
3' slotted angle bar (~$8.00)
(2) 3/8" x 5" bolts
(4) 3/8" ID x 2" OD fender washers [Steel] ($0.37/ea)
(4) 3/8" ID x 2" OD fender washers [Neoprene] ($1.00/ea)
(2) 3/8" wing nuts
(1) 1/4"-20 x 1 1/2" bolt (for camera mount)
(1) 1/4" nut and washer

Video is here. I have a cooler video, but it's NSF EvoM.
http://www.youtube.com/watch?v=kp91ls0R6lg