Without a doubt, metallic gray turbines are the best wheels. Period. So if you will have 18" or 19" turbine for the M3, I'm sold.
Now pricing might be a peculiar proposition. It appears as though current pricing for the turbines for the S (~$1900 for 19" and $2200 for 20") is meant to undercut Tesla's offering on 21" turbines at $4500.
So seeing that for M3, the wheel upgrade is only $1500, I wonder if the plan is to also try to undercut Tesla again? Might be a tough sell with 19" M3 turbines for $1900 vs Tesla's 19" NON-TURBINES for $1500. But at the same time, tough to justify to S customers that M3 19" turbines are less expensive than S 19" turbines, even though they're roughly the same size.
Tough.
I'm in no matter what for metallic grey turbines and you just solidified my choice to go silver on my M3.