I have a 2002 Honda Odyssey EX with factory CD Player. I want to continue using that radio and install an amp for the 4 speakers, new speakers, my sub enclosure and an amp for the sub.

I know how to install speakers, 6.5 inches. I have the subs all set. My questions is about hooking up the amps.

1. What 4 channel amps can I use with the factory radio?
2. How would I hook it up properly?
3. Where can the 4 channel amp be located in the vehicle?
3. How would the subwoofer amp receive the audio signal?
4. Would there be any risks to using 2 Amps?
5. Is there a way I can hook up everything to be 2 Ohms?

Thanks for any help.