Hi I have an 03 S2000 the second plug in the HU is for the changer. There is no problem adding a tweeter to the wireing to the doors. That said the twweter in the 03s is in parallel with the "woofer" using a so called bass blocker which is a capacitor. This is a cheap way to do it instead of using a proper crossover. The real problem to adding seperate tweeters to the door is physical, ie mounting them. As was stated earlier, why not get speakers with the tweeteers installed inside them. The bass blocker (or crossover) will already be taken care of.
Andy

 

so what about splitting the 12V outlet. Is that possible?

 

[QUOTE]Originally posted by xviper As for splitting the power of your accessory socket, NO, you will not cut your voltage by 1/2.

 

I SAW THAT WOODSON! I WAS LOOKING FOR MORE INPUT... SMARTASS!

(damn, I looked over Dave's post and completely misses it...DOH!)

 

You should be fine Steve.

I can cut tweeters into your door panels for you if you'd like. Just mail them up here.