WELL
For a temporary fix (which I have been doing for years now

):
When it begins to rattle, just push the open (back) button a TINY bit...just for 1/2 a second.
It won't leak or anything either...trust me....it doesn't open it at all just shoves it back a bit. I've left it in the rain, washed the car, etc. after pushing it and it's cool.
Of course, it is just temporary, but will work OK until u decide to fix it.
later
PS sorry if u already knew the trick
OOPs sorry didn't see it was when it is open....for that, just reverse it and push the close (front) button a tad.