Well, it's absolutely true, you really can teach an old dog new tricks.
The Princess can't take a flying leap and jump in to the back of the car at the moment. She thought about it long and hard, then wisely realised that it just wasn't a good idea at the moment.
She stood looking at me, so I patted the bumper and said "paws up" and stood with 'my paws' to give her the idea. Then I said "paws up" and she duly put her paws on the bumper, allowing me to hoik her not inconsiderable rear end in to the boot.