I've got a Topeak trunk bag with fold-out side panniers I've had for about a year now. For rain during commute I've just been wrapping a poncho around the bag and hoping it doesn't come off, but I see Topeak makes raincovers for their bags. I haven't been able to find a website that sells them (or any rain covers for trunk bags at all) so I thought maybe someone on the forums would know something about it. Does anyone know where I can find a waterproof bag with a tight elastic opening (damn it!)?
I contacted both the Canadian (Lambert) and American (Topeak) distributors and neither of them have the raincover available for the Trunk bag (mine is the DXP). The American distributor said that they may end up getting them in June (now) or July from Taiwan. Other than waiting, they have them here:
I have been using white garbage bag containers and ziplock bags. My only issue is that I bring my bike inside and park behind my desk, when wet, the bag drips and makes a bit of a mess. With a raincover, I can easily avoid this problem (and not have to bag everything, everyday!)