Give it some more time. He needs to get use it first. By the way, does he prefer his old carrier? Some of them don't like too much space when it comes to carrier. They feel more secure in smaller space.
I use a hard carrier we got from Petsmart. It was made by Petmate names Kennel Cab which has a
seatbelt slot on top so you can secure it while driving. My puppy wasn't crazy about it at first but learned to love it quickly. If she sees us getting ready to go, she would be sitting in the carrier all ready to go.
She sleeps in it too when she was little and still do if she gets tired or bored during the outting. She prefered her bed at home as it is winter and it's getting cold now.
I am wondering, as we would like to get a soft carrier also, how do you secure it in the car?