What's an extremely cheap, low tripod head?

I own a kombi and i got the idea to buy a really low, small tripod head that i could stick onto the dash and mount my camera, effectively making my car a giant, 4 four wheeled tripod. I think it would be really handy and i could use heaps of long exposures while driving et cetera.

i was just wondering what everyones opinion on an extremely inexpensive (i'm talking extremely cheap), low yet sturdy tripod head. It should be able to support a nikon d300 and a 24 - 70mm.
i've been searching the interwebs and have come up with a few options such as the Velbon PH-25, SLIK Standard Ball Head-II, Manfrotto 494 Ball Head or the Giottos MH-1002.

any opinions or new ideas are greatly appreciated and have a good day

Added (1). I already own a tripod

The one that comes free with a tripod!

Check Amazon.com, they have plenty of mounts from super low priced to the highest level pro equipment. You'll find mounts there that allow you to solidly place your camera most anywhere you can think of.

A 1/4"-20 screw and a piece of plywood is extremely cheap, compared to a tripod. You might be able to find a roll of duct tape for even cheaper.

Not certain if your camera (or car) will appreciate such treatment, but if cost is your motivation…