NSU Wankel Spider
For much of the 1960s, the future of the internal combustion engine remained up in the air. Felix Wankel’s rotary design emerged as a credible alternative, being both smooth and compact, and it’s no surprise that manufacturers were clamouring to build their own versions. The first production rotary ended being the NSU Wankel Spider, an open-topped variation on the Sport Prinz theme. It was potent little car – the 497cc rotary put out 50bhp and pushed the Spider to over 100mph – but proved too expensive and unreliable for serious sales success.