Originally Posted by New_m3
I'm using Vredestein Wintrac Xtreme in 245/35/19 and 275/30/19. They fit fine on the stock 19 inch stock rims. You could try searching on google's shopping section for them.
There is a stock 18" winter wheel and tyre package from bmw for the m3. Maybe this is what your garage was meaning?
I did a search and found a few suppliers. Do you have a website where you got them from? Thanks