Sirus radio
Thomas,
If the Sirus unit has the ability to have a low level signal output you can use the aux input cable from Coastal etech. It goes between the unit indash and the factory cd player. The sound quality would be better. The FM mod unit will degrade the performance of both your AM & FM tuner. The additional pathway for the signal from the antenna to the radio will affect the already weak performance of the factory tuner. By using the FM mod you are limiting the response of the satelite radio to that of the FM tuner in the Prius. Signal to noise and dynamic range will be limited. I'm not up on Sirus, but XM units such as the Pioneer and Dephi can be modified to give a preamp signal. If you must use the FM mod unit the antenna on the stock radio is on the left corner of the unit. A reach from the glove box. To remove the radio remove the lower trim by pressing in on the black clips center point. Remove the clips, the rest of the lower section has clips and will pull off. There are 2 screws holding the radio panel, remove them. Set the parking brake, shift the car into B, press down on the trim panel where the hazard switch is pull towards you, remove the 2 10mm nuts. pull the radio bezel from the bottom and unplug all the connectors (they have push in release tabs) unplug the antenna and remove the radio pod. The hardest plugs are on the screen. I reccomend 2 people to save some skin on your arms. You can get 12volt and accessory power at the radio plug. Hope this helps. Perry...