AV In and Bulletcam

I would like to order a Bulletcam so i can do some shooting externally on my car, i have seen the kit etc however the ask for AV in i have a Sony Digital handycam DCRpc4E which doesnt seem to have this feature listed in the manual

A couple of questions

1. is there any other way of achieving the same result using this camcorder what i want to do is get some external footage while driving a sports car on a track ie from behind without having to hang out of a window.

2. Failing using my Sony, what is the cheapest adequate camcorder on the market that i could use just for this purpose

Thanks in advance


Tony