I've got a real vw radiator with the tubes and fins like a trans cooler and have no problems. You have to remember the big block chevy guys use them on drag cars with no problems
But part of it is the fan I have, its from a passat and is a little long because the passat has the same style radiator just a few inches longer but has a single motor and dual fan driven by a belt system. If you don't mind junkyard parts hit the yard and look for a early 90's passat or audi which has the same thing.
The motor is big and a two speed unit but the corrado motor is shorter in lenght and doesn't stick out in the way as much and bolts to the factory vw shroud.