My godparents used to have GSD,and he used to do that,,,but they lived in a small town and he went in the bush,the dogs would just run WAY ahead and if they wanted to,they run run besides the car,but they drove really slow.Then after they would get out of the car and just go walking outside with them,he did it very safely and the dogs loved it!
Now they have a Husky/malamute mix,and a Chow/husky mix,and i dont think they do that anymore..

but that does bother me that he makes them run along side the truck???and he's doing it where other people could possibly hit the dog?? thats very dangerous...i dont agree with it.