Home Theatre with car subwoofers

First time poster but i was just looking into hooking up my old car sub woofers to a home theater system i was about to purchase. The subs are 10'' 500 watt max 4 ohm pioneers and the guy at best buy who seemingly knew what he was talking about said i would only need the home theater system, and an AC/DC converter to power my old amp to supply additional power to the subs. i figured i would ask some others who know what they are talking about before i started rewiring the room. Thanks in advance