there a write up about making a mount for a camera if u have removable headrest in your seats its a little shaky but if u put rubber around where the headrest meets it would reduce vibration, also instead of the one stick just sticking out of the seat i would make some sort of 'leg' that i could bolt it to the floor or something
heres a fast draw of a idea of using the rear strut bar as one of the bases... it wouldnt be that hard to fab up something to hold the strut bar or fab something close to this with stuff from homedepot or places like that...
hope it helps...
if u have gutted trunk and no rear seats its really easy to find hole to bolt a idea like this to...