Just to update, I started this thread, and thanks for all responses.
When "harley" went down to garage, he was confused on what happened to his old familiar car.
I had put one of his old "blankies" in the rear seat, so he would have a familiar smell.
Well after the third prod to get him,he jumped in the direction of where your feet would be, if you were sitting in the second row.
His rear paws went to the side rails. After that he put his rear feet up, and climbed with no problem up to the rear seat, where after two minutes he promptly fell asleep.
What a good dog.
He know knows this is his truck, and will watch it for me, when I have occassion to leave him inside, if the weather is cool enough.
He still looks for the old car first, but waits for the new trucks door to open to hop in.
He also likes the stadium seating, so he can see me much better.

Much regards