I bought a set of Michelin Sport A/S Plus Tires sized 235/45/18 from TireRack a couple of months ago and, like an idiot, opted not to buy the Road Hazard Program ($100).

Well, last night I ran over something sharp or something on the road and now my rear passenger side tire is flat and the front passenger side is losing pressure. I'm going to see if I can repair the rear tire but things aren't looking too good.

What are my options? I know it's not a good idea to change just one tire so I've been looking on craigslist for a pair of tires and I guess I would just throw the good tires on the rear and put the craigslist tires on the front. I really need to be able to drive a pretty long distance by Monday/Tuesday so I'm pretty desperate right now.

What tire sizes would I be able to run in the front if I had 235/45/18s in the rear? Or would it be at all okay to just throw a different tire onto the one wheel on the rear passenger side?

 

Patching is not an option?