A used Porsche Cayenne is arguably one of the best performance SUVs that money can buy, and will cost you thousands less then a new model. The Cayenne, based on the Volkswagen Touareg platform, is a lean, mean machine that combines the space of an SUV with the speed and handling of a sports car, and when you are buying one used, there are several things to keep in mind while you shop.

1. You are almost guaranteed to be going through a dealer, so get ready to haggle. It is very hard for a private seller to sell any car worth more than $30,000, and the Porsche Cayenne is definitely above that threshold. Dealers are going to likely be your only option.
2. Despite being touted as a performance SUV, the Cayenne is offered in a V6 model as well as the more powerful V8. The V6, the more common model, is of course priced lower, but you will notice the loss in power at the pedal. On the high end of the scale a V10 option is available, and a hybrid model is on the way.
3. It does come in a manual transmission. For the sportier driver this is an important option, and one not normally found in SUVs. It will take a bit of searching to find one, but the potential benefits in power and/or fuel savings may be worth it.
4. It is expensive to run and maintain. Fuel economy for the Cayenne is rather dismal (11 city / 18 highway for the V8, not much better for the V6), and the Porsche badge means that you will pay more for routine maintenance like oil changes and brakes, and common parts like light bulbs.

So what's the final word? The Cayenne is nice. It is fast. It is a Porsche. Expect to pay at least $45,000 for a used one, and if you want really nice options and blinding acceleration, you might be shelling out in excess of $80,000. So search around, compare dealerships, empty the piggy bank, and brush up on those haggling skills!