finished the vents up today.
incidentally this is my 3rd attempt at this post! better not accidentally close the window AGAIN!
made a few changes to the design. when you look on the photos of the side vent mesh, on the outside top corner its got the mesh there, i cut this back to the contour of the vent hole as it was fouling the crash bar. also, its too tight to do what i initially planned, which was to be able to put the side vents in with the bumper on, so i could still use the lower mounting screws, but with the current design thats not possible. however, the bumper is perfectly secure without them.
decided to cut off the centre vent supports with a stanley (and my palm, ouch!), as it didn't look very good with them there. tested it on my blue bumper (that i'll smooth sooner or later!) and it was to no detriment to remove them. touched up the bare plastic bits with touch up paint, completely unnoticable, but they will be perfectly smoothed on the new bumper.
as i didn't want to permanently stick the mesh to this bumper, i used double sided foam on the tabs, and its holding up very well - very strong stuff.
as i didn't want any light bits showing through, i made sure i painted black both the lower mounting bolts below the crash bar and the temp sensor mounting on the bumper.
anyway, less talk more pictures!:

this is all the mesh for the 3 vents cut to size, with the tabs glued on. i also gave it a few coats of matt black to match the colour of my top grille mesh, and also as cutting the mesh leaves some whited areas.

you can see the centre mesh mounted here (and my lovely working shoes - deathtrap!) with the tabs snugly fitting round the vent.

and here where the double sided foam is

the passenger side

and the drivers side
and a few of the finished article on the car:



