Late afternoon LA time my PCM repeatedly powered down mid-drive powered back up, Porsche badge, Cayman badge, then returned to tuner. This happened constantly for the entire drive. Ddi not matter if I tuned to FM, same thing occurred, but tuner would return to XM after power down. Spoke to Rusnak dealer here in SoCal, he's been getting calls all morning. It seems a bug in XM satellite software upgrade is responsible, unclear if limited to Porsche, but seems to be effecting slightly older, (mine 2014) PCM's.