My girl does that too. Front part in and back end is down, then they stare at you like saying, "A little help?" LOL!
I pull my girl out and make her catch some momentum so she can jump in. Before, she hated cars. She threw up almost constantly in our cars. To get her used to it, I hid treats in my car for her to find while it was parked in the garage. Great activity for her. Now, it's her favorite place to go.
Abby - Jan. 1, 2011 to Dec. 27, 2013
Bandit - Sept. 17, 2012
Rogue - Feb. 14, 2014
"A tired dog is a happy one