A:AnswerThat is a safety feature to prevent you from watching a DVD while driving. To get around that simply attach the parking brake wire on the back of the unit (Park SW) to the ground wire.
A:AnswerMy vehicle already has Sirius radio, but I think they have to hook it up to the JVC unit. A Best Buy technician would be able to give a more accurate answer. I have a 6 week wait to get a Best Buy installation appointment, so I'm not the best person to ask.