Watch the Wiesmann Spring Festival at the factory in Dülmen, Germany. About 50 Wiesmann cars where present that day. This video shows a couple of Wiesmann GT MF5 Roadsters. The GT MF5 Roadster is the most powerful convertible Wiesmann has ever made. It is fitted with a BMW 4.4L V8 twin turbo engine, developing 555HP and 680Nm.