for the extra dough...consider a motorcycle or go kart and trailer combo for the X5? For sheer speed, you can't go wrong. Or a used performance car...plenty of them under 10k.

I considered supercharging mine..but then, after thinking the majority of the time I drive, this truck is plenty fast. This truck does 140!!!! Cruises easily at 90 mph, handles phenominally well and gets good looks once you put the 20" wheels on. Once I thought Supercharging, I immediately thought of upgraded brakes, wheels, and suspension...ADD THAT to the list too!!! Plus it drastically decrease your gas mileage.

I personally feel that if you are going to put whatever money in this truck is (and I've gave it serious thought) what others have been doing..asthetics and enjoyment INSIDE the cockpit will be the best.

Personally, I've done the following:
Better dustless brakepads (I'm happy with that Akibono<sp?> stuff)
Subwoofer (absolutely required imo)
20" factory looking wheels and tires (ok so is not inside..but cool factor is there)
Radar Detector
Factory SunShade
Car Cover
Radar Detector
Radar Detector
Radar Detector

I've been toying with the idea of a back up camera

These are not "speed mods" but they definitely make your ride so much more enjoyable. If I want speed, I just hop on one of my motorcycles or my vintage firstgeneration turbo RX7 that is modified and get the giggles...nonetheless if I was to race say for a very long distance with various weather condition...neither my toys will beat an X5. My fastest time ever on a typical 400mi trip was with this truck.

I recall having fun with a Dodge Magnum, STI, MLs, Durangos...all were just shocked that this factory 5000lb (with driver in it) truck does so well in speed and agility contest...all with the a/c and stereo on.