Tight sods!
At Man it's free, because they use areas where they cannot get a car.
The bike parking area for T1 is under the ramp up to the multi story carpark, directly opposite the Jet2 check in hall. It's dry, well lit and even has CCTV covering it. Also has ground anchors to lock up to.
I'm sure there must be somewhere similar at Stansted that could be used.
MAG suggestion box anywhere?