Garmin’s GFC 500 autopilot has now been certified for nearly all Piper PA–28 and PA–32 single-engine airplanes following FAA issuance of a supplemental type certificate to install the unit in Piper PA–32RT-300 and PA–32RT-300T models, Garmin announced.
Source: aopaGarmin GFC 500 approved for two more Piper singles