I've got a fast dog

So...this last week Jaime has been acting up. Aggressively. Today he was at my parents house and I guess he started his aggressive streak that includes stalking and growling Kuma the akita. My mom puts Jaime in his place, flips him over and yells at him. He is so scared by her dominance that he pees. Right after she disciplines him he follows her around and respects her to no end.

I go to pick him up in the afternoon and he only has eyes for my mom, I guess he likes control. I go into the front yard with him. My mom gets in her car to go back to work and I go to get my bike to bike home. Jaime freaks out that he can't go with my mom in her car. She backs up and leaves the drive-way. I figure he will stay with me, like he always does. But no. Now that we have established my mom as the boss he turns and chases her car. She doesn't hear me screaming after him (he doesnt hear me either) nor does she see him chasing her car. She turns onto 8th street and starts driving. Jaime is running, glued to her bumper, at close to 30 mph. I get on my bike and chase the two of them. Cars pass and stare and point...there is a dog in the right lane running the speed of a car. There is a car behind him, leaving him room, just like any car would. He continues to run for a few blocks in the lane, at the speed of the other cars. Sam who is sitting in the back of my mom's car stares out the window and watches Jaime the whole time. My mom realizes he is staring and looks out her window to see what he is staring at- a blur of fur. She pulls over and sure enough Jaime tries to jump in her car with a huge smile on his face.

The pound lied. My dog is no Australian Shepard mix. He is some sort of Greyhound.