I love the scoobies. It's like university points, or like the "F"'s on Stacy's charm bracelet, but funnier than either.
I was thinking that Amanda would effectively be going to a school of D/s the whole time she's on the truck. She will be trained thoroughly, but not necessarily subjugated.
She could be forced into either role at Tucker's hands, or even have to sub to Him and Domme her momme at the same time. Either way she will find her own natural kink by the time the road trip is over. And I still think it's Domme. It's just more fun, and will make the 3-way dynamic ever so much more interesting.