Coachbuilder Baur based in Stuttgart developed the Topcabriolet for BMW to delight friends of open-top driving. This was a version of the BMW 3 Series that allowed the entire roof to open up by means of a hard top and a fabric top. However, the side sections and a roll bar contributed to passive safety. Baur offered the Topcabriolet with all engine versions and 4,595 Topcabriolet sports cars were built in this way based on the first BMW 3 Series.