If a 500bhp Cayenne Turbo isn't a good starting point for a tuner car, we don't know what is. Adding 50bhp and 96lb/ft of torque (for a total of 612lb/ft) the Titan BTR 550 should live up to it's monstrous name. In addition to the engine mods, the Titan benefits from a sports exhaust that's switchable between loud and not-so-load, air suspension and an aerodynamically efficient carbon fiber body kit. It's also available with 22" wheels up to 11.5" wide. No word on what sort of premium the Titan will carry over a stock $93,700 Cayenne Turbo, expect that info at the Geneva Motor Show.
[Source:Geneva Motor Show: SpeedART Reveals Cayenne Based Titan BTR 550]