Please help! How do you add subs to a factory system in the 2008 dodge Avenger...plays music fine, I want it to break glass...factory has no bass..please help!

Try a hammer.

Line out converter + amp + sub

If you werein any category near breaking glass, you'd be using something better than the factory H.U.

But yeah, a LOC will work fine if you want to use the factory radio.

what line converter do i need for a 2000 dodge ram 1500

Any. LOC's are universal.

If you're just adding subs, the 2 channel LOC from that link would be fine.