Trying to determine the tallest tires I can get away with on an R56 JCW. It's lowered about half an inch. I'd like to use 215/40-18, on an 18x7 wheel with a +42 offset. Can I get away with it without rubbing? I have been using all sorts of fitment calculators online, and the differences between what I run now, 215/45-17 on 17x7.5 ET+45, are very small. What I can't tell, is whether or not even a small difference would be too much...anyone running something similar? Thanks