i watched my friend do full interior neon once, and have known how to do it forever now its so easy.
just go to a local automotive place and ask for a fuse interceptor, fuse tap, whatever they call it.
i could do a quick how-to tomorrow if you would like. my way is cleaning and you can run it to a switch to turn it off during the day and on during the night. but if you do what some people probably do is just wrap the hot side of the wire in the interior fuse and they stay on all the time or something.
if anyone else is interested in a how-to ill be glad to do one.