If it's a heat thing then Super might help. The ED cars are so restrictive of air entering the engine bay that I expect the whole area runs hot. 95%+ of my mileage is claimed back at 40/25p so even V Power would not cost nearly as much as I claim back.
How easily is the cover removed?
@ 335i E92 - I would be interested in the half-price coils but the list of cars on the thread does not include ED 330's with the N53 engine - or not in the quick scan of it I made!