Leaves and pine needles down the front intakes

Any one got a solution, excluding a full external cover, to stop pine needles and leaves from going down the front intakes whilst parked.
My S2 lives near some scots pines, and whilst I hope any going into the engine bay will work themselves through, I dont want to be taking off the front clam just to clean it out.
This may sound petty to some, but I do get hundreds of them come down every time it get windy.
Oh, and chopping the trees down is not an option.

How about 2 pieces of ply-wood cut to fit over the grills. Heavy enough not to blow away and will keep the needles out.