Burnout Paradise, Unbalanced?

I only ask this because I've noticed when I play online I get stuck with not such an amazing car while everyone else has the cop car that completely leaves me in the dust. Am I missing something? I'd prefer not to have to buy any dlc but will if it's an absolute must for beating anyone online.

The DLC cars are a bith unbalanced in the sense that they slightly edge out even the most powerful cars already in the game.

The GT Nighthawk is one of the better speed cars out (DLC), along with the Delorean rip-off as far as stunts are concerned (easy to safely do double barrel-rolls on a lot of jumps in that puppy).

There's the hot rod as well, but it's almost uncontrollable at its max speed due to boost being locked once you hit it, and it is extremely susceptible to crashing on the smallest of things, so I'm not counting it.