Quoted from polyacanthus:

My wife is usually the one to help me move games. And we have about the same strength so we work smarter not harder.
Lay a blanket over the bumper to protect it. Cut a piece of cardboard and lay it in the back of the car near the bumper, on top of the blanket. Stand the game up on its back end and spin it around so the bottom faces the car. Spacing is important here so you might have to try a couple times but you probably want the game to be a foot and a half from the car. Tip the game down onto the bumper so it's resting there at like a 45 degree angle. Now use the bumper as a fulcrum point as you both lift the back of the game. The trick is to lift the back and flip the coin door end down onto that cardboard which is a sled that will slide on the carpet making your life way easier. So it's a lift and then slide.
If there is a hump for the rear seats you'll need a couple 2x4s as rails but the cardboard will slide nicely on them too.