Just bought a civic 03 ex today. Does the stock radio have the rca jacks in the back. The preamp out puts. I wanted to know because i have subs from my older accord. I know my accord did

 

i don't think your radio has preouts. you need to get a high/low impedence converter(i believe thats the technical term) if you want to use your stock radio. it gets wired in parallel with 2 speakers and takes the high input from them and converts it to low input, and has rca jacks on the same box which would run to your amp. some amps have this feature built in.

 

My LX doesn't - you will need a high/low impedence converter. You can always pull it out and check.