I'm working on choosing new wheels for my 2013 specimen, I already made up my mind and want 18x7.5, but my only doubt is offset. is 40 too much? will it rub or otherwise create problems that would make the car a pain to drive, this is my daily so driveability is paramount.

 

For 18" wheels, assuming you use an appropriate tire size*, you should be running an offset between 45mm and 55mm to ensure no rubbing.

* As for the correct size for those wheels, you should run 215/45 R18 tires.