yes, in tha Kam's Script you have to choose COL, then you just need a general shape of the car, therefore you can use the chassis_vlo, once you have it you can export it, the file needs somethings as boundin sphere and some other materials or something like that.
What i do is to open a .col for an existing car (in the COL tool you select open col and select a dff file.) and then i reshape it, once i'm done i export it as a .col file.
Now you can export the .dff by selecting your new .col file.
hope it works for you.