evoluzione.net do a nice lightweight one.
avail from aprilia.me bout 30 quid I think. You need to trim the plastic 'wings' on the undertray. 5 min job tho.
Ck
oops, I always ask if things are in stock b4 ordering...well apart from the Cf tank that OPP racing kept me waiting 11 MONTHS for after quoting3.
I would also have made one if I had the time/inclination.
CK