daannnnieelso your parents would kill you for taking your own vehicle out of town for a couple days? Or is it their ride?
or are your parents super religious?
I honestly can't see why they would be upset. Sure, it might be weird to tell them that you're going to chill with a girl for a couple of days and all but if you're funding the trip yourself I can see 0 reason why anyone would get weird about this. My parents were always super down for me getting out of town for a few days when I was your age, regardless of the situation.
The thing about religious fam reminds me of when I brought a girl that I was friends with out to this cottage thats my extended family's for the 4th of July. My aunts showed up at one point with my grandpa. Anyway. One aunt randomly decides to stay their cause she's tired or something dumb. Then stays up reading. Makes the vibe super awkward for my friend. Anyway one room has bunk beds. We stayed in there and slept on opposite beds. Not like the walls even go to the ceiling so we weren't fucking or anything.
Anyway she called my mom and bitched about me sleeping in the same room with a girl.
Shit was so dumb.