Finding someone to do anything different up here is a problem, got one quote $600, so I did it myself yesterday . It was a bit tricky with the bonnet still on the car and would be much easier if you take it off,
Bought a sheet of lite Aluminium as it is easy to shape, $32 from Bunnings and made a cover to go under ALL of the vents, sealed and bolted it on to the skin under the bonnet, added a hole in the front that is just to the side of the radiator where I will make up a funnel and hose that will let the water out without going on anything. Well that my theory
I did leave it opened at the back just to see if the vents can still keep it a little cooler, this could cause a problem but it work fine if I just tip water in through the vents BUT I will have to wait until I fit the funnel and drive in the rain to check it out, maybe the wind factor under bonnet will force me to modify it, bloody hope not as it is on there to stay