I am trying to install an aftermarket stereo in my audi. I have talked to many techs about what is needed to do so, and was wondering if there was anyone out there who has already done it. I know that i need a harness, antenna adapter ( i think) and something that has to do with the factory amp, also is there a factory amp in my 99 2.8 a4? i do not plan on using stock speakers so i assume it not necessary to use the amp thingy if needed

 

Open up your trunk, if you have a rack on the driver's side then you have the bose amp. If you are going aftermarket speakers then you really can't use the amp as it has some unique speaker impedences.