add sub to stock car stereo?

I have this Toyota stereo deck model#36404 and CD deck model#34230 in my 1998 Rav4. I don't have any problem with my stereo and so my speakers my question is: I bought this 12" Pioneer Sub few moths ago now. Is it possible to add this sub to my existing unit. Usually from the back of the aftermarket system there is red and white RCA jacks for the speaker output where you can hook these wire to the power amplifier also you need a remote wire to turn on and off the amp but i don't think i have these wire from my Toyota stereo deck. just want to know if it can be done before. Thanks

Piece of cake, you'll need an adjustable line-output converter, an amp kit and a little bit of time to wire it up. The output converter will have high-level inputs that you'll need to connect to the speaker inputs (be sure you get your polarities right). Next, connect your RCA's to the low-level outs on the converter and connect to your amp. Get out your mulitimeter and find a wiire that shows +12v when the key is in the ACC & IGN positions, drops to 0v when the starter is cranked and shows +14v when the motor is running. You can find this at the radio or in the ignition harness. The rest is just like a regular amp install.