turn the wheel to lock, then try and mount it up with the 5mm spacer. maybe try a 10 or 15 ,usually can only get those on slip on with extended wheel studs. a 20mm spacer will put you at 0, which might allow you to dial the camber back in.
edit:
here is an 18x11 0 on stock metal from the wheel fitment thread
being a half inch smaller should give you a little more play room for tire size or camber