If you're trying to give the car motion, you'll have to blur only the car, or only the background. Currently it looks like the picture was taken during an earthquake Here's one I made as an example:
You just made my day, thank you. Yeah, I jumped down the road and while landing backwards it caught on the pole with it's side and yeah... That was the nastiest one I do think. Well, they didn't survive either...
Why Build The Bridge In Sadler Gorge, Instead Jumping Over It? (Allthough Biulding The Bridge Is Fun)