Savington, I feel your pain.
I've avoided summer events because of oil temps.
I take my oil temps at the exit from the oil filter adapter where it typically reads ~20*F higher than the crank case. I don't think I've ever gone over 285*F indicated but after finding my temp sender reads 15*F low I really got puckered.
I contacted Amsoil and talked to their technical support. They say their 0W-30 I run experiences shear at 304*F. I told him I change the oil and filter every 3-6 hours. He said not to worry too much about the shear temp with the maintenance frequency I practice. He said the thing I really need to watch is the flash point at 420*F. Makes me wonder if I had the most astute tech guy on the line. He strongly suggested I send an oil sample in for analysis to see what was really going on inside the engine. He indicated I should be real interested in oxidation of the oil.
My intercooler is pretty big and blocks the majority of the rad in the lower bumper cover opening so it's not too feasible to install something lower in the front without significant rework.
I'm going to put a 24 row back in horizontally between the steering rack and radiator. It will be in series with the one in the nose and recieve oil flow first. If nothing else it will dump heat radiantly and be most effective getting max temps first, then on to the air cooled unit. It sits right on top of the under tray. I have the under tray swiss cheesed there but never felt I got flow through the unit. I think I'm going to add a louvered panel to the bottom of the undertray to help encourage flow out under the car.
I'll be running VIR South Course in 3 weeks. It's pretty brutal with a lot of high rpms and frequent shifting. If it works well there, maybe I'm on to something.