Paint vs polish is a matter of preference really
I like polished stuff cause it stays clean, wont discolor or flake and is easy to maintain. Plus, any hoazz can squirt some paint on a manifold in as long as it takes to pull it. Add like ten hours of hard labor to that for polishing that manifold alone.
'85 528e, Mr. 528i-brand new euro e30 323i head, 325i cam, polished/ported intake manifold, ireland headers to 2inch glasspacks x2, 535 AFM, custom chip. Soon to run 325i motronic 1.1 w/ chip. I laugh at your mildly tuned m30. Muahahaha.
'83 528e-3 speed auto new paint and interior. "i" cam, still slow. 175k.
'88 US spec M6- My Dads. If he wads it I'm makin an M5 (if it ever drives again). Got transmission? 140k.
The actual engine would be under all of that
carbon fiber crap. Nothing fancy about a stock M54.