Nothing. Your gear is more than up to the task, it's all about the skills of the person wielding it.
I think these have potential, but I agree that a more interesting location would add a lot. In addition, make sure to think about the lighting, in this case primarily the time of day. Finally, try to shoot from unique angles that emphasize things like the car's stance or suggest motion, power, or anything else you'd care to emphasize about the car. These three things are the differences between your pictures and the Subaru picture. Also, tell your friend to paint his bumper (seriously, I never understood that), or find a different car, preferably one that is all the same color (imagine how much less attractive that picture would be with a primer bumper).
His equipment is more or less the same as yours, it's what he's doing with it that's making the difference.