I agree to the concept of rear drive chassis for this HHR S10 pickup .
I have used a Malibu frame under a 54 F100 it worked out very well after hours of measuring and planning, I plunked a 46 Chevy pick up on a S15 chassis really not that hard, you just have to show some attention to details and maybe that's what this cat was trying to do, and the dented fender and door could have happened after he ran outa cash and parked the project!