I saw a small dog with his head out of a backpack once on a bike. I thought that was so cute

I had wished to get a little wagon or something to take my dog in when he was having a hard time walking, but I know he would've jumped off as soon as it started moving and hurt himself. Next dog (if/when I ever get one!) I'm going to train to ride the cart or if it's small enough to be in a crate strapped to the back.