I installed the Sportster4 in my truck. I hard wired the power into the fuse box. The thing that gets tricky is that the Sportster does not run on 12VDC. It is lower like 4 volts or something. What I did was disassemble the outlet adapter that comes with the Sportster beacuse it has a voltage reducer in it. I soldered on the power and ground wires to the contacts that would normally go into the cigarette lighter. I then tapped those wires into the fuse box. Instead of using the mini-jack aux port in the truck, I wired it into the back of the aux port. There are three wires that are a very small gauge so the soldering is tough if your are not good at it. Now all I have to do is turn the radio to aux and power up the Sportster and she works. I can also still plug my Ipod into the aux jack. To mount it, I cut the suction cup swivel off the window mount and drilled a hole through it. I then mounted it to the cover that goes over the rearview mirror mount. It is a perfect fit just above the mirror. From what I have seen, the Sportster5 is identical to the 4 except it has a color screen so this should all apply to you. Please let me know if you want some pics, I could take a few tonight. Good luck!
Chris
Chris