Audio Systems: small question, internal amps, rca line

Question
I have a small question, i dont know if you will be able to answer it... lets say that my car stereo has 200 watts of power.....but i also have a 4 channel 200 watt amp going to 4 speakers does that mean that the total output power would be 400 watts divided by the 4 speakers? or would it be just 200 divided by 4 speakers because the watts don't add up?

Answer
car stereo = 200 watts (or 50x4)
4 channel amp = 200 watts (or 50x4)

It depends on how you wire it up, but basically the reason for an external amp is to allow you to use the RCA line level outputs on the headunit. This will then let you bypass the decks' internal amps.  You can tell by the size and wieght of the 200 watt amp that the headunits' 200 watts is not as beefy. External amps are a better option 999 out of 1000 times.

Wiring the decks' speaker wires to the amp is NOT adsvisable in any case (you would then be using the amp as a booster and not a dedicated slave ... = damage). Only use RCA line level outputs to send signlas to an external amp..

As to how you get your 200 watts, you are looking at an either/or situation and I would say to use the external amp ONLY.