Deal alert - found an interesting bag for my Moulton Mk III
I bought a cheap ($19.83) Sunlite bag for my commute bike from REI outlet recently and wasn't paying close attention to the specs, but when I received it I realized that it's a better match for the wide rack on my Moulton Mk. III. The bag is unusually wide and it has an insulated main compartment that holds 12 cans, plus a removable watertight liner. Neither the REI page
nor Sunlite's website
mentions the fold-down panniers which I think are kind of cheezy, but they might not be bad in practice if they stay out of my rear wheel.
It does have a removable plastic bottom stiffener, but it will probably sag over the edges of a standard width rack, and it will certainly hang over and interfere with panniers unless your rack has a lower rail. It's not for everyone, but this bag seems like a great deal if you've got a wide rack to mount it on.
Did I mention that it's an enormous bag?