Try emptying the water system and replaceing it with summercoolant,
also fit a seperate fan switch in car so you can have more control over
when the fan cuts in.

You can also try using bonnet raisers to help let the heat out,not everyones
cup of tea i know but ive got a set on mine and to be honest i really dont like
the look but they seem to work. Ive also got thermatec heat wrap around my
manifold,turbo and downpipe

Hope that helps a bit