The Lamborghini Miura SV/J was born from the mind of Bob Wallace, Lamborghini's famed test driver and chief development engineer. Knowing full well the potential of the Miura, Wallace started work on the original SV/J in order to coax Ferruccio Lamborghini into racing. The J in the name comes from the FIA's Appendix J racing regulations, the series where Wallace had intended for Lamborghini to compete. With numerous weight saving measures such as extensive use of an aluminum alloy, as well as plastic windows, the SV/J was almost 800lb lighter than a production Miura. Small exterior changes were also made, with the headlights fully enclosed, as well as the addition of a front spoiler. The SV/J used the split sump version of Lamborghini's 4L V12, but modified by Wallace to produce around 430hp. The chassis also saw numerous modifications in order to create a vehicle more focused for the track, significant features including a reworked suspension, and the use of two sill-mounted gas tanks. Unfortunately, Lamborghini never entered racing, and the original SV/J was sold to a collector, eventually being completely destroyed in a testing crash. Although the original never survived, there are an alleged 7 SV/J cars in existence. These factory built cars were made to full Bob Wallace SV/J specifications, and are the most desirable and rare of the Muiras. A disputed 8th SV/J exists, made by Lamborghini from an unused Miura chassis for one of the then owners of Lamborghini. This SV/J is not considered to be fully original as it was produced in the 1980s, well after Miura production had ceased. It is also common to encounter SV cars that have been privately converted to SV/J specification. An original factory built Lamborghini Miura SV/J is a true treasure, but not one that is easily or cheaply found.