After the concert the same person wheeled me right to our ride.
What songs did they play in the concert?
Playing the same 30 year old songs over again.
Oh, that sounds like fun. It is good that they were able to help you after the concert, and it would be good to show your appreciation for their help. They didn't have to but they were kind so a thank you would be appropriate.
I am wondering why I should thank someone for helping me get to my car.
It's socially expected, and kind, to thank someone who helps us, particularly when someone goes out of their way to do so. It  acknowledges their action and expresses our appreciation for it. Don't you feel better, and more inclined to help, when someone thanks you for things you've done?