I choose not to wait till Bachmann restock their uncoupler [in a month or so] so instead I purchased several 'Totally Hidden Uncoupler'. Now these do not come with track or that little signal figure.
Installation that I used was a section of straight track turned over and a coating of rubber cement on the underside of the plastic roadbed {let this air dry completely} - put the four magnets on the corners of the metal plate which is provided. Top the magnets with a touch of rubber cement. Once it is also dry place it on the bottom of the track. Looking down from the top - rails - roadbed [underneath roadbed {hidden} four magnets and metal plate
I have found this seems to have a little more strength for the uncoupling.
hgcHO.