I can't help but giggle when I read your response...my daughter was the SAME WAY!!! I thought she was the ONLY baby that didn't like to be swaddled! But you know, all children are quarky, just as adults are. Part of the difficult thing about being a parent is getting to know a new person, when they can't talk to communicate! :)
Take a deep breath, laugh at the fact your child has to do everything "different" (I know that helped for us...) and try to think "outside the box". There's nothing you can do about the car seat...for her own safety, she has to ride in it. Maybe try sining her songs or something (probably something you've already tried doing)...but that worked for us...I remember there was months we couldn't listen to the radio becuase my job was driving...and singing! But at least it kept her content.
So...good luck! And keep trying different solutions...you'll eventually find something that works...or even better...she'll grow out of it! :)