The GT4 reportedly takes the GT3's ethos of more power, less weight and stickier-than-glue handling and brings it all to the Cayman. As these photos show, there's a much lower air dam up front with a cooling vent at the tip of the hood. Larger wheels are another obvious addition and are likely shod with some very sticky rubber. At the back, there's a double spoiler combining a wing and a ducktail.
The power and gearbox for the GT4 remains a mystery, though. The rumor is that it uses a tuned version of the 3.4-liter flat-six in the Cayman S and GTS to make between 370 and 400 horsepower.
A similar overhaul of the Boxster might be on the way, as well. A version of the convertible wearing some of the Cayman GT4's goodies was recently spotted testing. That one even had a manual transmission to make the prospects behind the wheel even more exciting.