Threats that the National Highway Transport Safety Association (NTHSA) would soon pass laws effectively banning the sale of convertible automobiles in North America prompted Porsche to create its 911 Targa, and subsequently a whole new vehicle type, in 1965. Porsche replaced the top of the 911’s roof with a removable panel to allow for an open-air driving experience, but everything from the B-pillar back remained in order to appease NTHSA safety regulations. Porsche went one step further and reinforced the remaining vertical pieces with an extra-thick steel roll bar -- just in case. Obviously the NTHSA never actually enacted its ban on convertibles, but the 911 Targa proved to be enough of a success that Porsche still sells a Targa version of the 911 to this day.
