Got an 07 coupe with the 19" rims/susp pkg.

Have an opportunity to buy an OEM 225/45/18 (from the Performance pkg) with tire for sale. There should be no issues using this as a full size spare for either the front or back correct?

 

EDIT: Didnt read OP's post right the first time

 

Yes I know the rears are slightly larger but why would that prevent me from using an 225/18 OEM? Even the spare doughnut could be used to temporarily replace any of them.

 

true... as long as its only for temp use then you should be fine

 

will it fit in the trunk?!?

 

I just did some rough measurements... diameter of about 26" and width of about 10". That pretty much eats up the entire trunk, lol.

 

^ Anything more than the wheel well is pointless unless you intend not to utilize the trunk for anything other than housing the spare. Honestly if you blow your 19's, throw on the 18" spare, sooner or later you're going to have to switch it back to the 19". Unless the 18" is free, I wouldn't spend money on a spare.