I ordered some Beyern Mesh 18x9.5 et45 for the rears. Will I just have to massage the inner fender to get this to fit? Maybe a 3mm spacer? Any one know?

I dont have experience with 18x9.5"s, but I do run 17x9" et 45 with some 265wide tires.

YOu will probably need a 3mm spacer with the extra 1/4" closer the wheel will be to your chassis compared to mine (I dont need a spacer, but i get some rubbing under hard cornering).

You'll also need to roll the outer fender, and hammer the inner fender. Also will need at least -2.0 deg camber. If you run wider than a 255 wide tire, it will also be more difficult. Good luck.