For the M3W the bevel box noise varies from car to car from virtually silent to screaming. It's characterized by occurring in a fairly narrow speed band (or bands) typically between about 50 - 70 mph.
A first port of call to reduce the noise is to check the drivebelt tension. You should be able to twist the lower run of the belt between 45 -90 degrees and go towards the looser setting.
The BB oil has a limited effect but over time Millers EP140 has proven a good choice. For info the Redline 250 "designed for the M3W" has only worked in 1 case I'm aware of but several of us tried it and changed back to Millers straight away as it was significantly worse..
There are 2 fundamental issues, the shape of the gear teeth and the bearing mounting. The JB-Engineering fix addresses both these with a new set of gears and an improved bearing mount.
As far as I'm aware nobody has tried fitting a Super3 bevel box to a M3W so it's not guaranteed to fit and could still be noisy. .
