We Can’t Keep It a Secret – Subscribe Today at Huge Savings! Save up to 73% off the cover price. PLUS FREE digital access. Valtteri Bottas flashes me a broad grin as I settle into the passenger seat of a 1980 Mercedes-Benz 500 SL Rallye. As the Finnish Formula 1 driver aims the prow of our coupe towards the start of a smaller handling circuit on the infield of England’s Silverstone racecourse, I share that this is my first ride-along with an active F1 driver. “Firsts for both of us,” he laughs. “I’ve never driven this car.”  Understandable, given that this is the only rally-ready SL Mercedes ever made. Back in the late 1970s, Mercedes-Benz had fashioned a few SLC coupes into off-road machines, but believed that the shorter and more nimble 500 SL would be better at rally dominance. Four such examples were built and Walter Röhrl was tapped as the top driver. But before the start of the 1981 season, Mercedes backed out of rallying, choosing to focus on other race formats. The coupe we’re sitting in is believed to be the last of the four units remaining. Entering the track, Bottas guns the V-8. A shorter axle ratio was engineered to provide more torque off the line and i...