I am prepared to donate a moderately used tool bag for toting the relay items. This came with a cordless drill set that has already passed it's useful life. It is fairly water resistant (not waterproof) but the banner and baton are both vinyl and the log/composition book will be packed in a ziploc. You can see from the dimensions that it measures about 8" wide, 14" long and 9" tall and holds two one-gallon jugs nicely. There is a connector on each end of the bag for a shoulder strap so it could be slung across a riders back if tie-down is not an option. I should be able to dig up a padded shoulder strap to toss in with it along with a couple of bungee cords. It is pretty stout and I would be willing to bet that it would withstand more than a couple of "Get-Offs" at highway speed, praying that any "Get-offs" involve THE BAG ONLY. Wheels down!
I haved used this bag to tote gear for hunting alligators on more than one occassion, so a good CSI might find traces of lizard blood...