help!! how to add a subwoofer

I have just bought a 2005 murano without bose and I im trying to figure out how to add a subwoofer to the factory radio for better sound.

I have just bought a 2005 murano without bose and I im trying to figure out how to add a subwoofer to the factory radio for better sound.
Quickest and easiest is to just add some sort of prepackaged system like Bazooka. http://bazooka.com/productAutoPassiveBTsRX.asp?id=157

Then get a small amp and line level converters to hook the OEM radio to the amp. Don't waste extra money on some high end sub unless you change out the OEM radio. You'll be wasting money if you do.