I am looking to build a spare for my Compass through Discount Tire/Tire Rack etc. I've searched this forum without much success, Does anyone have the size of the wheel and tire for the non-matching OEM spare? I have the 225/R18 OEM and I really don't want a donut spare, and I think I can do better than the $300 that FCA wants. I just want short term to get me back on the road. If you have built one that fits (with the shelf in place) could you please post the sizes you used.