There are two main types of lambo doors: bolt on lambo doors and universal lambo doors. Bolt-on kits are specifically engineered for the given vehicle application, and universal kits are not. Therefore bolt-on lambo doors are generally more expensive than universal lambo doors, but they are much less difficult to install relative to universal lambo doors. If you ever need help how to install Audi TT lambo doors, call us at 1-800-419-1152. Also, if need be, you can buy individual Audi TT lambo door parts, such as just the lambo door shocks.