Chrysler 300

I would guess it's either a busted hose, busted overflow box (the box where you added the water), busted radiator, the thermostat, your waterpump or worse case scenario a cracked head gasket. You would need to have someone else add water while you rundown exactly where the water is leaking from but it will be one of the parts I listed for sure as that is pretty much all the parts associated with the cooling system in your 300. Hope this helps and hope it's not a head gasket cause that's expensive.