The latest Techart Magnum is full of carbon fiber and packs a 930-horsepower punch. There are plenty of tuners ready to sell you a tweaked Porsche Cayenne. Techart has done just that for years, and ...

It’s the Geneva motor show next week, which traditionally brings madly tuned performance cars out in force. It’s the event where the most famous (and infamous) tuning houses go elbow to elbow in the ...