Anybody add a subwoofer to the stock system in the LSV? This is a 2008 with the stock Kenwood deck plus two tower speakers and 6 interior speakers. There are two amps but I haven't even looked at what they are.

I am curious as to whether I need to add a separate amp or if I can use what's there just to add a 10" sub. I know that a subwoofer was an available option but I don't know if they would run it from the same amps or use different ones or add a third one if you ordered the sub. Anybody been through this?