Does painting/powdercoating rims black on a red 370z look unprofessional?

Telephone

It's all subjective.

My eyes feel as if black wheels have a cheap/bland feel to the car. Maybe I relate it to steel wheels on a base model-beater car. Black rims give off almost a dirty vibe. Chrome rims give off a ghetto vibe. The clean stock 370z rims give off a sexy, sharp, chic vibe. But again...that's all subjective. I personally like 5 star silver wheels...simple, sporty, blends well with many cars, and they're easy to clean.

Some guys love black or chrome rims. Some don't. Get what you like...because you're not driving a Lexus in the first place.