Worst case is that you won't have the navi info on the DIS and your navigation will be a little fuzzy. The RNS-E should turn on, you should be able to listen you radio and SD, you should be able to enter a destination and get route guidance to get there. With the wrong tire size it may need to recalibrate, when coded for the wrong car the sound may be strange. But you can't really break anything by not coding it right away.