"Fittage" did you make that up?!?
I feel your pain though, sorta. Even though I've only been doing maintenance on a stock Z4M, I've already had to invent 3 "BMW special tools", and one of my clever swap-this-for-that ideas cost me 2 hours hovered over the intake manifold at #5 cylinder -- you know, the one that's basically 4 feet from any outer edge of the car!