Eventually they arrived near a hill, a section of fence lowered itself and they drove over it towards a rock wall at a part that was obscured by bushes. The wall opened and they drove right through it entering the tunnel that was just wide enough for them. Dave was oblivious to all of that as his outside senses were still disconnected.
Finally they arrived at a larger hall, various people were busy about doing their business, or at least pretending to be. As they stopped, Steve opened his door and leapt out closing it behind him. Then Jeff pressed a button and Dave realized that he was about to turn back. "Wait, Jeff is still inside", exclaimed Dave. Jeff just grinned, "I know".
On the outside a lot was happening as Dave changed back from truck to badger, but inside the changes were rather modest. Some controls had changed, but otherwise you could easily mistake it for still being a truck. As Dave shrunk and changed back to his new furry self he was on his hands and knees, immobile, "Hey I still can't see or move". "Sorry, forgot something", Jeff explained and reconnected some of Dave's senses. Dave got up and looked around himself, he realized the tunnel he was coming from and took a run for it. After Dave had gained some speed, Jeff stomped down on the brake pedal causing Dave's feet to lock up sending him into a tumble causing him to stop.
Steve came to Dave helping him up, "Well we can't give you to much freedom just yet. You see Jeff inside of you is like a driving instructor, if you do anything we don't want you to do, we can stop you, or make you do things." Dave nodded and got up.
They went down a tunnel and in it was a bronze statue of a bunny. It was completely nude and was clearly sporting an erection. Steve gave it a little rub on both the boner and the bum, and from the looks of it it was clear that was done a lot of times before. "W..What's that", Dave asked. "Well he tried to escape, but don't worry he'll be turned back soon, was his 5th time. Sometimes I think he likes being a statue."
All three of them arrived at a little cabin with a bunk bed, "Well this is where we'll be for the time being", explained Steve, "Any questions so far?" Dave asked, "Well I don't know if that's to personal, but I can't help but notice there something being odd about your ass. I've felt it when you sat on me, and", he points at Steve's bum, "one can see it through your shorts". Steve pulled down his shorts and revealed that there was a pipe seemingly stuck in his asshole. "Well the transformations don't always go perfectly smooth, but that's not really an issue. Next time I'll change that'll most likely be normal again", he got closer to Dave, "We could play with it in the meantime if you want".