I fit checked the ST60 on my 18's before buying the ST40 instead. Spacers are a must for clearance which I did not feel comfortable as a long term and permanent solution.
Even with spacers, clearance is minimal. Probably between 1 and 2mm which is a bit concerning if anything gets stuck inside the rim (piece of rubber, rock, etc.). Be careful and check the inside of your rim often.
2009 E90 M3 | SG | FR | 6Speed | Akrapovic Evo | JRZ RS1 | StopTech Trophy | Cantrell Brake Ducts