Hi guys, just seen a full set of BMW E90 M Spider Spoke 193 Rims (18") for sale and am interested but need some tips on how to check for faults (i.e. wheel rotation problems; wobbling from side to side; etc.). Am not skilled in such technical matters but I assume I might need someone with the equipment to check for rotation problems, etc. What do I do? It's a private sale. Also how do I check they are genuine original BMW rims - I have a 2009 BMW M-Sport 325i with 17" rims and want to change up to 18" rims.