Sorry but I just don't see any difference in the silencer/exhaust or its mounts pictured to all other Brooklands M3W pictures I find everywhere.
These are from the official site, and from cars still without the louvres/vents at the back:


And this is from MO63WLR's car, the one where the exhausts have cracked. Still can't detect any difference ...

One thing changed though. When I ordered mine and because the Brooklands car was announced and released before the 2014 revision I specifically asked (when in the factory) if a 2014 Brooklands was a 2014 car (reinforced chassis, bump steer corrected, bevel box corrected, centa compensator, cool down fan, and whatever else less known they may have revised). I was told it was, with the exception of the back louvres.
Now, apparently, the Brooklands car will have the back louvres also. Don't mind if it does, don't mind if it doesn't, but it's interesting that they changed their mind about it.
Still, what worries me is the exhaust problem, apparently a Brooklands specific issue.