Time to experiment with the flip front a bit.
After a bit of mild chopping it looks like the front could be fitted with a slight lift so that the plenum sits inside the profile of the bonnet...
The 'ventilation' gap doesn't look too bad, so it could work. Not sure - we will revisit this !
Lets bodge the hinges on for a bit of testing and use some bits of wood to work out where the supports will sit.
A quick frame was tacked together to check the hinges work as expected.
It seems to work as expected, so will have to think about a final design that better follows the lines of the front.
The flip front does include A panels, but I've still bunged on some steel ones. These have been extended vertically which should allow easier fixings and will accomodate a bit of 'lift' if needed.