They go to the backseat of the car

"Here," Mackenzie groped around the trunk until she felt what were the backs of the back row of seats and pushed them forward, exposing the main cabin of the car to the couple. "That should give us more space," as she crawled from the trunk onto the backseat.

"Okay, Kenze," Matt followed her, still rubbing his balls from her kneeing. Mackenzie kept crawling until she reached the shotgun seat and looked around the front. Matt, on the other hand, kept looking around the back.

"Well, Matt," Mackenzie suggested, "do you know how to hotwire a car?"

"Kenze, this isn't the 80's!" Matt protested "don't you have your keys?"