BMW introduced the fourth generation 3 Series Cabriolet in the spring of 2007. The biggest novelty about this model was the three-piece electronically-operated retractable hard-top (revolutionary new device within the BMW range) and enlarged rear & side windows for better visibility. Another innovation developed by BMW and fitted into this latest generation Cabriolet consisted of a Sun-Reflective Technology leather upholstery. The 3 Series Cabriolet was based on BMW's new E93 automobile platform and initially came with a choice of 325i and 335i variants. Later on, the model received several small engines for a wider range to choose from. The top-of-the-range 335i model benefited from a 3.0L twin-turbocharged unit delivering 307 hp that was mated to a standard 6-speed manual transmission (6-speed automatic with steering-wheel-mounted shifting paddles was also available as an optional feature). Car's on-road performances were very impressive too, with a 5.8-second score on the 0-60 mph sprint and an electronically-limited speed of 155 mph.