commonrail:
I tend to shower in the day when they are quieter and clean.
And that would be…? 
In the day…then you wont need one when you park up at night,thus giving you more options.
I used to have a UK wide pure gym membership excluding London for 19 quid, used many a gym and shower before parking up at all times of the day and found quiet places to park that id never of known where there. Defo much better then 90% of showers that are available otherwise bar the odd customer that has a clean one.