You have to just rotate it 180 like mentioned above. If you flip horizontal, you end up with text that requires you to read the equivelant of right to left which isn't right for the english language.
So in order to maintain the left to right the M will be at the bottom of the cab on the left site and at the top of the cab on the right side. No way around it.
Otherwise just get two of the same image printed up and you're all set. Not sure what any other issue would be.