You can make it pretty quick with a few upgrades. That car really isn't that slow to begin with though. I think it does 0-60 in 6.4 seconds? That's pretty good. I believe the average 0-60 time for most cars on the road is around 8 to 9 seconds. If you throw a good cat-back exhaust, ECU Tune, Cold-Air Intake, Sprint Booster it will make up noticably. The best thing to do as far as looking for more indepth upgrades is to look a Mercedes Benz Tuners specifically upgrades for the SLK320. There is a pretty good aftermarket for the engine itself, just not much that is Crossfire specific. I think what you will find is the overall performance of the Crossfire is HUGE! It's hard to beat it in the Braking, Cornering and Top End areas. If you are used to going fast in a straight line, you may want to try a few local AutoCross events and see what this car is truly all about.

The SRT-6 has a hand-built AMG engine that is almost entirely different than the standard NA 3.2. The internals are forged, the compression is lower, it's balanced and blue printed and otherwise indestructible. The SuperCharger won't fit a standard car. If you want a 13 second car, do the above mentioned mods and give it a 50-75 Wet Shot of NOS.

Enjoy the ride. Eventhough it isn't a a high-powered car, I think you will find it very rewarding to drive.