Sophia getting on with Sam in the car would probably confirm that her opening up to Sam/Zack/Dylan is driven by a pining for her younger, early or even pre-Liam days, so yeah, maybe she does get lost in the moment and goes for it. Setting up a scenario where she and Sam are alone isn't too hard to imagine, but I'd question whether it could be done without arousing suspicions?
Having said that, I hope it doesn't go with the ride home for the simple reason is that it's an all too common scenario, I'd like to see something new. And please, please no hanky panky of any sort in the bathroom stall.
I also hope we don't get a backstage meet and greet because that's a new custom setting with lots and lots of characters (band members and their other friends, plus Sophia and her entourage), new props, posing cups and bottles, a block of dialogue about how on earth did they get beer?!! They aren't' old enough to drink!! Teasing Sophia to not be such a prude about underage drinking, Sam announcing he didn't drink because he's the "designated driver" so Sophia thinks that's so mature of him, he's so responsible - unlike Liam, so irresponsible. (+1 Sam). Ugh.