All 3 of my children were this way, my last two being the worst. It was almost depressing having to take a car ride anywhere with the baby. We also tried EVERYTHING and honestly, nothing but time works. They eventually grow out of the "I hate my carseat stage" and fall into a " I LOVE my carseat stage". She's already 5 weeks, I think my kids grew out of this around 8 weeks so hang in there, I know it's hard but she WILL stop, I promise you it won't be like this forever.
I still remember when I went in for my first 6 week check up after having baby and the nurses and staff were all like "ohhhh, we were hoping to see the baby" and I said "sorry, NO WAY, my baby HATES the car seat and I won't take him anywhere I don't absolutelly have to". I still remember one lady was so surprised hearing that and she thought all babies loved their car seats, but that's not always the case. Many hate the car seats in the beginning and then grow to love them. Good luck and hang in there!