Doug's Take The BMW 1 Series is an incredibly enjoyable modern BMW thanks to its small sizing, fantastic chassis, and great powertrain options. This particular example is a 135i Convertible, boasting a 300-horsepower turbocharged 6-cylinder and a 6-speed manual transmission. It also touts the Sport Package, an M Sport suspension, and some performance modifications that should make this 135i even more exciting to drive.