im using the buttons on mine for my door lock/unlock on my alarm.
i just got the door poppers today.
im so sick of having to use my key and reaching over to let people in.
$10 isn't bad, but you would have to find all of the other parts.
i got a everything i needed for my dads for like $40 or something.
look on www.car-part.com
and i think its listed under gps/navigation.
if you get one from a junk yard, make sure it had the stupid gray sockets for the lights in it, someone ganked em from the one i got and i didn't notice.