The term VW Precursors refers to the three models of cars that preceded the Volkswagen Beetle. The first model was the STU, which was a three-letter acronym for 'Stromlinien-Tourenwagen-Umbau', meaning 'Streamlined Touring Car Conversion'. The second model was the RSTU, which was a four-letter acronym for 'Rear-engined Streamlined Touring Car'. The third model was the QRSTU, which was a five-letter acronym for 'Querlenker-Rear-engined Streamlined Touring Car'. All three models were designed by Ferdinand Porsche and were the precursors to the Volkswagen Beetle.