Your engine is much more exposed than ours is. Ours appears further forward:
The front "hood" on the Axis/Vegas units pretty much touches the radiator:
A big difference between the larger F53 units and our smaller E350 units.
Another difference: Sitting in the driver's seat you are pretty much sitting on top of the front wheel. In the Axis/Vegas units we are behind the front wheel.
I'm sure both of those differences changes the noise a bit, for example: since our engine is further forward it may not make as much sense for us to insulate the floor from noise.