I took my 2012 Rider's Seat to the Cool Covers HQ a couple of weeks ago.
They had a Cover available previously, but it was designed around the Small Tank Seat design, so didn't quite work properly with the later type.
The Central Strap fouled on the locating Lug of the Seat.
They've redesigned it now, with twin Straps, fits all models.
Pillion Cover unchanged, fits all models.coolcovers.co.uk/product/moto-guzzi-stelvio/