I kind of like the idea of a rack trunk bag, I have a Nashbar one, but I never use it. The reason is that I can't figure out how to properly attach a light. I've never gotten either a SuperFlash or my current Dinotte to mount well behind them. I've been thinking about putting a bar of PVC pipe on the back of the rack to mount lights and still use a rack trunk. What do others do? The fabric loop on the back of the rack trunk is bollocks; the light just points any old way and is useless.

I bought a pair of Nashbar ATB panniers for $24 I think, about 4 years ago. Still going strong. They do let some water and mud in through the seams on wet days though, so I'm still vaguely interested in using the rack trunk to at least keep my cargo out of the tire splash zone.