I used a VW radiator, I think it was a Shiroco (sp?) anyway it was aluminum and very thin, maybe two cores. It had plastic tanks and very small inlet and outlets, the same size as a heater hose. I mounted it behind the rear end at about a thirty degree angle. I used it just like a heater core, using the heater inlets and outlets on the motor. I used a two hundred degree sensor on it which triggered a electric water pump. No fans on it, but I did have one on conventional radiator. I have a couple of idea's for your car if you are interested.
Ken