Not trying to change the topic but I think with the S30, getting air flow through the radiator is probably more important than which radiator to choose. I have read the JTR and the thicker 100% aluminum radiators do an admirable job of cooling, more than adequate so long as they have the air flow through them to remove the heat. A good fan is part of that, reading through the windtunnel discussions, the Aero modifications like ducting the grill opening directly to the radiator opening all 4 sides, sealing the core support all appear to have the largest impact on improving cooling efficiency.
sorry for off topic.