You "can do" whatever you want.
It will most likely make the stereo get hot and shut off or activate a protection circuit. This might take 1 second or 3 years, but loading the little built-in amp with more speakers than it was designed for will shorten the life of it.
I would recommend just adding a small amp to drive your pods. There are many amps on the market that can be quickly wired to your factory sound system and supply enough wattage for the 6 1/2" speakers. Without knowing what you have in the pods, I would guess 25-50 watts per channel is all you need.
Good luck!