sound activated led's

Hey everyone thanks for help in advance.

I am kind of new to the wiring scene (i have done it before but just kinda winged it and hoped i didn't blow anything too important up.  But i want to take a kind of big project if it is worthwhile (in other words if it is at all possible).   But as far as resistors and relays go i'll probably need baby steps through it if anyone is willing to bear with me.

what i am trying to do is setup a sequence of sound activated LEDs to go with my car stereo (preferably bass) but noise alone is fiine.  I would like to have 4 green leds 4 yellow leds and then 4 red leds and at lower volume onle one two or three leds will light up depending on how loud maybe even all four then have the sequence continue into the yellow and then the red as it gets really loud... obviously i'll need to be able to adjust sensitivity for my stereo but would it be easier to wire 12 leds off something like the jaycar neon tube sound display (which i'd have no idea where to start on) or have three seperate smaller noise activated modules one for each color...

I drew a picture in paint but i am on a school comptuer and can't save it so hopefully i was descriptive enough to start.

doing a little research i think something like this would be my best idea

http://www.jaycar.com.au/productView.asp?ID=KC5322&CAtid=&keywords=neon+modulator&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

does anyone know i would wire this device to only light certain LEDs at a time would i need twelve individual sound activated devices?

also i was looking at the sound organ but that seems more concerned with sound frequency than noise level.

(i am baisically trying to create a fancy looking sound meter that isn't really accurate but just makes people go ooohh ahhhh.)

Thanks agian for help....