1. Guns : I think they would use magic ammo. Like you fill a clip somehow with a certain type of magic. Pulling the trigger would release the magic. Depending on the magic is what it shoots. Like fire, ice, metal, etc.
2.Cars : I think they would use magic. It could be a fire spell, a wind spell, or whatever spell you want. They would have to be made so that ponies can control them though.
3. ?

1. A different pony uses the mirror pool. (like there is 10 applejacks)
2. #1 but add the poison joke to it. (like 100 tiny applejacks)
3. ?

1. Overdrive:link
2. The ghost:link

1.Where AJ and RD switch body's.
2.Where AJ/RD grows 10x their normal size(not in weight).
3.?