There has been several, highly misleading sales tactics stating that an automatic transmission does not require a radiator with a heat exchanger.  These sellers suggest that "true" performance cars will use their radiators and an after market cooler.  This is highly misleading, if you have an automatic transmission, you NEED a radiator with a heat exchanger built in.  If you have a racing/high performance vehicle, you need the heat exchanger AND an after market tranny cooler.  Some just sell radiators not up to the snuff and say things to compensate for a poor radiator design, just remember, if their radiator is so great, why can't they make a heat exchanger in it??