If it's R17, then you have 17's.
You will be able to run the standard setup of 225/40 18 up front and 255/35 18 in the back.
As for color, that's tough. I have a TiAg LCI E90 identical to yours. I ultimately chose a mix. Gunmetal and machine faced. I think hypersilver is classy, but to me it washes out with all that silver. Looks awesome, but not enough contrast.
Then, you get black wheels, which to me look meh on a TiAg E90.
So there lies gunmetal. Just begging to be on a silver car. I think that color, or the machine faced, with black in the back like the AG 359's look insanely good on our cars. Here's what I chose.
