How cool is this scenario? You sit down with your friendly neighborhood Chevrolet dealer to order a new Tahoe, and amid the usual post-deal jabbering about fabric guard and paint sealant, Mr. Salesperson says, "Are you interested in adding a supercharger, a three-inch suspension drop, 14-inch brakes with four piston calipers, and a set of 20-inch wheels?"

You heard that right.

At select Chevrolet dealers around the country, you can add go-fast parts to your new truck before you drive it off the lot--all of which will be covered by a real warranty that mirrors what your rig had from the factory.

These dealer-installed packages by Dyno-Proven Products can be as mild or as wild as the owner desires. For a complete Chevy Tahoe performance makeover, which Dyno-Proven calls its XS-425 package, you can expect to pay as much as $15,000 above the purchase price of the vehicle. The result is a 425-horse Tahoe, Suburban, or Avalanche that digs into a turn and stops like a sport sedan.

The XS-425 Tahoe we drove was equipped with Dyno-Proven's Cool Charger centrifugal supercharger, a three-inch suspension drop, 20-inch polished alloy wheels shod with Z-rated 305/50R20 Toyo tires, upgraded shocks, and a brake package with 14-inch cross-drilled, slotted rotors, and four-piston calipers.

The rumbling exhaust note from the cat-back system first alerts you that you aren't driving a stock 5.3-liter Tahoe. Stick the shifter in drive, and the XS accelerates with authority and without the typical blower whine. This is because the CoolCharger isn't driven internally by gears but by a Kevlar belt. In the turns, the Dyno-Proven setup keeps the Tahoe level and understeer is all but gone--though the factory's steering feel remains. But perhaps the biggest improvement is in the brakes. The original brake pedal feel is replaced by firm, confidence-inspiring stopping power.