I want to get 18 inch rims and have seen some 18x7.5 and 18x8.5. I don't want the rims to stick out!!!! I want them to tuck under the fender cause I can't stand to see rims stick out!!It looks so much better tucked under the fender. What does offset have to do any way?!?? Can't you just tell simply by the wheel size. I don't understand what +42 and +55 means I have no clue!!! Can someone please break it down!?!?!??!