I can see that my Chipper would probably love going out in the sidecar like those dogs in the picture, but he is so short that he could not even see out, let alone fall out.
Still, I don't think that I would take the chance with him, just in case. You never know when a dog is going to see something that he just has to chase.
I got Chipper one of these Outward Hound doggy seats, and he used to ride in that when I had the mini-van. He preferred sitting on my lap, but the seat was safer, and he did stay in it, and liked having his Elmo toy along with him on the trip.