Looking good. For the chassis paint issue, I suggest masking off the engine and exhaust and shoot it with some Dull Coat.
This kit's a little fiddly, but if one takes time picking out the details, it does build into a decent looking model.
I'm working on converting one back into a hearse. It's a long, slow process and I got stalled by a couple of issues I don't yet have the skill to address. But seeing yours makes me want to start on mine again.
David G.