1. The 1990 Audi 90 Service Repair Manual is a comprehensive guide designed to assist Audi 90 owners in maintaining and repairing their vehicles. This manual covers a wide range of topics including engine, transmission, electrical systems, and more, providing detailed instructions and diagrams to help users troubleshoot and fix issues with their cars. With this manual, Audi 90 owners can save time and money by performing repairs themselves, ensuring their vehicle remains in top condition for years to come.