SBC pump isn't noisy in mine.
Interesting - mine always made a bit of a din. It sounds like a generator kicking in on the other side of the bulkhead. As I said in the other reply I asked BSG Mercedes to have a look when I first bought it and got a "they all do that sir" answer.
storage
You can store things like phones and long life shopping bags under the 7th seat squab. I used to keep some tools, bulbs, etc in the spare wheel well.
In the car I used to end up using the door bins on journeys which isn't ideal for someone with minor OCD.