Looking good so far. I have the same kit that I'm currently working on. I've been debating on how to do the stripe on mine as well. The decal in the kit is not quite the right color and it should be metallic. It's going to be a little tricky to get right and still keep the black fade.
Also, I noticed on my kit while test fitting the front grill / headlight piece that the grill doesn't push all the way into the openings like it should. I had to cut the headlights from the grill and this allows the grill to fit into the openings like it should, then I'll mount the headlights seperately.
I haven't decided how much extra detail to add to my engine bay yet, if any. I'll most likely just add spark plug wires and maybe a couple of major hoses.
Your chassis looks great.