Thanks, Jesse. :) You're right, it's entertaining to see how LMM does things, and I spend a lot of time in slack-jawed amazement. 'Hilariously annoyed' might describe my mental state during tuning. :banana-dance:
Actually, what you're seeing on the bottom of the chassis (and good question, btw), comes from my guide solution. It runs a tiny bit too deep, and it stirs up all the crap at the bottom of the slot, which ends up trailing out behind the guide onto the chassis.
I've started using this guide solution because LMM always uses this guide (shallow) with stiff braids, and frequently solders the lead wires. Rather than desolder and fit a new guide, I just modify the guide. I'm a firm believer that you can make a runner out of just about any car without buying replacement parts.
I think anybody could prep this car in two hours. It took me a full racing night, lots of experimentation, etc, but the actual work is probably a 2-hour job. A fast tuner could probably do it in one hour, knowing what needs to be done ahead of time.