Im thinking about hooking up a neon so when I open my doors, it comes on with my map and dome lights. I can just tap into the fuse box and use the fuse as a power source for the coresponding function, right?

As long as the draw doesn't max over the fuse limit it should be fine.. worse case scenario.. you may have to run a relay triggered to come on by splicing one of the lights. It might turn off quicker then the fade though.. if your interior lights fades to off

you could just tap into the door wiring and when ever the power is given to the lights the neon gets power

you also can change the color of your inside lights. better IMO that tapping a neon into the wiring

Yea, a few months ago i spray painted the light lenses red (on the inside so it wont get funky) and it looks a lot better then the red gel caps I had been using for a while. I was just thinking for something under neath the seats or on the top, if it looks good.