This thread was from 2009 was me thinking aloud!
This is how I finally sorted it:
http://www.talkmorgan.com/ubbthreads.php/topics/27404/Dave_s_Diary_The_Story_of_the_#Post27404It looks better in the flesh than in photos. The angles make it appear slightly flat, but over seven years later it is holding up well. It fits against my undertray and channels air into the radiator lower tank.
This was how I did it on my Plus 4.
http://www.talkmorgan.com/ubbthreads.php/topics/161072/1