Starting with 1987, Porsche offered a reworked front end for the Turbo Cabriolet model, inspired by the famous 935 race-car. It was the open-top version of the 911 Turbo Flachtbau Coupe. After 1981, when Porsche introduced the 911 Turbo Flatnose (Flachtbau) for the coupe version, customers started to ask if the brand can do the same for the convertible version. At first, the German car-manufacturer didn't want to do that. Later on, the agreed and offered it as the option 505 for the U.S. market or 506 for the rest of the world. It was an expensive one since it meant that the manufacturing process was to take a completed vehicle, dismantle, and mount the new elements. In 1987, that cost was USD 23,244 (USD 53.000 in 2020's money). The car featured a flat, aerodynamic, front end, with the fenders flushed to the trunk lid. On top of the wheel-arches, there were air exhausts for the wheel-wells. All units were modified by Porsche by dismantling and reassembling already built vehicles right after they came out of the production line. That contributed to the car's aerodynamic and led to better performances on the road. At higher speeds, the front end was better planted to the road due to higher downforce. The 1987 model was better equipped than its predecessor. It featured air-conditioning, power-windows, and heated seats on the options list. The instrument cluster was the same as in the Carrera and there was no turbo-gauge. For the U.S. market, where 591 models were built, the 911 Turbo offered a reworked engine to comply with the emissions regulations. But that meant that the power was reduced to a mere 282 hp from its initial 330 hp. It was mated to a standard 4-speed manual and there was an option for a limited-slip differential.