I did that same thing.It was actually easy to put a neon in there I took a female cig. lighter plug, spiced it to the wiring. and I was ready for neons. Took not even 5 mins.
1999 Contour SE
Sony Xplod 50x4 cd player
Sony Xplod 1600 watt Class D amp
2 10" Flame-Q Audiobahns
35% tint done by Madavi's Motor Sports