Next up in the never-ending proliferation of Lamborghini’s Gallardo lineup is the LP550-2 Spyder. (In just the past year, Lambo has introduced the Super Trofeo Stradale, the Spyder Performante, the rear-drive LP550-2, and the Bicolore and Tricolore.) The first rear-drive convertible from Lamborghini since the 1998 Diablo SV roadster, the LP550-2 Spyder is a rear-drive version of the LP560-4 ragtop for a bit less money: $211,995 (plus yet-undetermined gas-guzzler tax) versus $232,095.The one-year-only LP550-2 Valentino Balboni coupe started this rear-drive-Gallardo business. Then, Lamborghini...