For any of you who have installed a backseat entertainment system, I have a question. Where do I connect the wires? I have a service manual on the way but it won't be here until the end of next week. So in the meantime any info on how you wired your install would be helpful. The wires I need are switched power, constant power, ground, and parking brake. Also, is it necessary to add an accessory power switch or just connect the power lead directly? Thanks in advance.