,
The massive rear wing is most certainly effective. Like most nose-heavy cars, the wing's angle of attack is nearly flat. From all appearances, the wing appears to be mounted to the rear trunklid, but we think there is likely some sort of bracing built into the trunk to help support it. 
The K-PAX Racing CF doors definitely aren't stock doors thrown into a mold, as the inner panels add some racecar functionality to the door. The black box appears to be a vent feeding air into a cutout in the dash.
The car has seen a lot of success over the years, and the K-PAX crew has proven that their Volvos have a spot in the World Challenge series with Vipers, Vettes, 911s and R8s. Sadly, we did not get a chance behind the wheel (K-PAX, if you'd like to remedy that, I'm available any time!), so I'll let the master behind the wheel tell us what it's all about:
“I’m on the plane to Detroit, where my #6 K-PAX Racing Volvo S60 awaits,shining and poised for two street ?ghts. Turf wars. The Swede in TheMotor City. Street courses suit us, because we have all-wheel drive, the only GT-category cars that do. By nature, most temporary circuits have lots of tight corners, where the big power of a Pirelli World Challenge GT car can be better utilized by the traction advantage.
Now I’m back home in Atlanta, and we scored a second and a ?rst! The Belle Isle circuit suits us, I’d say. When the Volvo bursts onto boost, it blasts out of the slow second-gear corners, as if shot from a gun. The same goes for the signature PWC standing start. Foot-to-the-?oor banging the limiter, then banging the clutch home so all four spin and it’s good-bye competition. Car owner Jim Haughey has a mantra: “P1 turn 1”.
The handling setup is a real challenge, because our K-PAX racers are a lot like the S60 street cars, still. Lots of front weight bias, 61%, limited by the series to adjust our speed, makes the setup like front-drivers. Big rear bar, no front bar. Well yes, it might be better to run one up there, but the rules have also restricted us to an open front diff, and that would cause dreaded wheelspin. That big anti-roll bar makes it want to snap oversteer the corner entries, while the front bias makes it want to push from the middle out. We balance these characteristics back and forth at every track. Engineers Dax Raub and Will Moody lose sleep over it, I’m sure. The Volvo is not a drifter, though I’d like it to be, and we always work for that feel at the edge of adhesion. On track, I keep it hooked up, because if it starts to slide the back, it wants to keep going. That nose weight also increases the load on our front brakes, which have the highest temperatures in racing, a constant challenge. Team boss Bob Raub says we have two brakes, and everyone else has four. It is a credit to the K-PAX team that this car can win against its world-class competition.
The engine is a small 2.5 liter Volvo ?ve-cylinder, with a big turbo, and so we drivers must time our throttle for the lag to build those 26 pounds of boost. In some between-gears corners, it’s a lot. Again, both the boost and the turbo are set by the rules, so we cannot improve these systems. It’s okay, because we have great races, and we even won the last one!”
