Detail Shop or someone tuning a 4 barrel carb. That would work.But there'd be potato chip crumbs everywhere when I pick up the car?
Being hyper-focused that way is great when listening to music or having sex or whatever. Not so great when someone's in a busy automotive shop dealing with constant interruptions in the midst of following precise instructions in a shop manual.
I'd actually be a lot more okay with it if it was a small one or two person shop (with them being slightly stoned, I mean, but never drunk).