[Chris L]

Thanks Gentleman thus far for the input. Although it could well be the best option, I really don't want to lift the bonnet and have ducting plumbed from top to bottom picking up the fresh air.
If I can't seal against the bonnet when its closed and locked properly then I will probably will duct and pick up air from underneath as has been suggested.
Mike and Gav.......you both answered questions I was suspicious about so thanks for that and thanks to the fellas that posted the pics..............nothing like a visual to get the message and ideas across.
Regards
Chris L