I have a 2 door with speakers up top and I fit a 31x10.50x15 easily without hitting the speakers.

I drilled a new set of holes for the seat latch brackets to move them a bit forward. then i bent and cut a new J bar to hold it in place. it fits decent but the tire side of the seat doesnt latch. the passenger side latched so the seat stays in place. beats the heck out of the spare laying down in the little bit of cargo space I have