I'm sure your little sweetie will get used to the car, and I'm sure she'll love going to puppy classes and so will you!
I took Roxey, and going to class is her absolute favorite thing (well, besides bikerides!)! For the first 10 min. or so she would kinda be crazy, but, after that, she knew what was going on & really listened. We have taken her to 5 obedience classes (because she loved going to school & it displinced her very well!)
and one agility class.
I'm also looking into getting a seatbelt harness for Roxey. One of our husky friends have them & say they are wonderful. It really calms them down alot.
Hope everything works out! Have fun!