Ford celebrated the Mustang's 20th Anniversary in 1984 by issuing a limited-edition GT model under the designation GT-350. The GT-350 name had not been used since the last Shelby Mustang was produced in 1970. The GT-350 could be ordered in either a hatchback or convertible body style driven by either the high performance 302cid V8 or the 140cid Turbo four. There was no official 25th Anniversary model from Ford in 1989, even though this was looked into with several designs on body and performance modifications. In response Ford modified the running horse badge on the passenger side of the dash board, stating "25 Years" on the bottom of the badge. These badges were installed beginning in April of 1989 for one year, until April of 1990, the Anniversary model year. After April of 1990, Ford kept the badges in place,without the "25 Years" portion. Ford also added "25 Years" water mark on the window sticker with the running horse badge during this time period. In 1999, Ford produced a special 35th Anniversary Edition of the Mustang. In 2004, Ford produced a special 40th Anniversary Edition of the Mustang. Available in both Standard and GT editions, it consisted of 40th Anniversary badging, enhanced interior, and a few "special" collectible items for the owner.