[Anthony B]

Mostly I used their cheap entry level ready to run cars to get a cheap chassis from them.

Are these available outside Japan?

A basic question...how do you attach bodies to them, for example, a Scaleauto GT3 1/32nd scale with 2 central body posts?

You attach a connecting piece to each side of the body, usually connected to a softish piece of foam rubber that you glue to side of body. This then attaches to the chassis with 4 screws. I will take a pic of one I used in the IMCA worlds to show how it is done...