Yes Tom its about the same as my castle but try it without then with. when i put mine on it was very hot
weather and i put it down to that fitted an electic fan and bonnet vents still cooking, then going to manchester on a cool morning on the motorway temp was creeping up but when i stopped at the end of the slip road it cooled down, but when i drove on it got warm again. I took the grill off and its been fine . I think the air hits the castle vortices around and stops any air going in.
Dave