I started running with my dog this past week. he seems to enjoy it alot and I still focus on keeping him within gun range so come this winter it'll be instinctive. It helps me stay in shape also.
I'm very relunctant to run my dog with my vehicle. 1. I don't wanna risk him veering infront of a tire and causing an accident. and 2. I don't think its a good idea to teach a dog to chase cars. Now I'm not saying that every dog that is run with their owner in a vehicle is gonna chase every car it sees or any for that matter. But I did have a scuba instructor that would have his dog run while he drove his truck. One day while I was at his shop outside of town on the highway, he let his dog out of his pen and the first car that drove by that dog was gone down the highway. Luckily he got his dog back shortly afterwards but theres only 2 things that happen to a dog that chases cars.
A bicycle would be ideal in my opion for your situation. You get the exercise and can easily set the pace and most importantly its cheap!