I checked the manual on my Viper 500 ESP alarm and it has a latching output mode that "will send a signal continuously when [the auxillary button] is pressed and will continue until [the auxillary button] is pressed again." This is exactly what is needed (along with a relay) to remotely turn on and off the Linksys WAP11 and Rio. I can take care of the voltage spike issue with a short delay time on the shutdown. I'm not concerned about leaving the player in the car. The only time it's even practical to remove the player from the car is when I'm at home and then it's in a locked, cool garage. Perfect for linking to my Linksys WAP11 in the attic and my cat 5 network and uploading MP3s. I'll post an update whenever I get this all setup.