This is a very interresting thread. I had read about the pressure reducing valve and was already wondering where I could get hold of something similar locally until reading here about the resistor mod.

It's quick and easy and makes logical sense, I will definately be going this route. Summer temps in my part of the world reach the mid to upper 30's with the car surface temps being way higher. Looks like a am a good candidate for a green shower if I don't do this mod.
Thanks to all here for the info.

Barry