modified retained accessory power

So I've read almost all the information available on this site on relays (learned a lot!  thanks!) but since I haven't had a chance to really go out and try anything out quite yet, I'm a little hesitant to go pluggin away at wires.  My intention is to have the retained accessory feature, but a little different.  I don't want my power to cut off when the door opens, I want it to cut off when the door closes.  I don't see why the original RAP relay setup couldn't be modified so that the pulse from the door opening would trigger relay#1 and the door closing would trigger relay#2 and thus tell relay#3 to turn off power.  I know what I just said didn't make too much sense, but basically my question is simply how do I do it?  I want my radio to stay on until I CLOSE my door.  Those last few seconds of music before I get out of the car are the most dear to me.

The car is virgin right now.  No alarm, no factory anti-theft, nothing to complicate things.

Please?  Any help would be greatly appreciated, I tried to figure it out on my own before asking, but relays are a new and mysterious concept to me.

yea, i went to radio shack today.  the guys there knew where the relays were in the store ... and that was all.  didn't even know what they did or were used for.  yeeeea, LOTS of help that was.

but since i'm a super genius, i think i figured it out.... on my own... oh well, you guys have been helpful with lots of OTHER stuff.  now i'll try it out this weekend and see if I'm successful.

thanks anyways?