2006 Cadillac XLR-v & 2007 Mercedes SL550

We know what you're thinking. How on earth can these folks hope to connect the name of the progressive Democrat president who steered America through World War I to this pair of plutocratic hardtop roadsters? Here's how: Wilson's likeness adorned the short-lived $100,000 bill, and Cadillac is asking precisely one Woodrow for its new XLR-v, including guzzler tax and destination charges. That's a one with five zeros, and it's more than four Grover Cleveland K-notes above the opening price of Mercedes Benz's new SL550, the benchmark in the stratospheric sun-tanner segment. Holy dead presidents! Can a Caddy legitimately command a six-figure price tag?

Its credentials are impressive, starting with a supercharged 4.4-liter Northstar V-8 that spins 443 horses and 414 pound-feet of torque back through a rear-mounted six-speed automatic that can be manually shifted. Chassis fortifications relative to the base Corvette-derived XLR include larger cross-drilled brakes, fatter 19-inch Pirelli Euphori@ tires, a rear anti-roll bar, stiffer bushings, and a revised calibration of the Magnetic Ride Control shocks for more body-motion control-especially when the shifter is placed in the manual gate to select the "sport" mode. Interior and exterior spiffs round out the V gear. Mercedes owns 45 percent of this market and isn't ceding a single percentage point of its share without a fight. Toward that end, the company has upgraded its entry-level SL with a fresh quad-cam V-8 that produces 80 more horses and 52 extra pound-feet of thrust than its SL500 predecessor's two-cammer did, routing it all through a seven-speed automatic. Quicker steering and more aggressive active-body-control calibration enhance driving dynamics.

To objectively assess Cadillac's fitness for duty in the C-K-note class, we rounded up an SL optioned to within four Franklins of the Cadillac, including Keyless-go, bi-Xenon lamps, a leather and wood steering wheel, and heated and cooled multicontour seats (all but the last come standard on the XLR-v), and headed for the hills and the test track. President Wilson was a Ph.D. academician, so if he were selecting between these two worthy roadsters, he'd probably want to start with an objective comparative analysis.