Well since thers no reply I figure I'll just give you my own experience... I don't really have advice heh
When I first got my turtles they were from NY's Chinatown when I went to go visit back in 97 (yea I know its bad to get it from there, but I didn't back then). I live in California and when it was time for me to go back home, I took the small plastic container, put half a inch of water and sponge inside, and placed my 2 turltes in there and went on my way. I kept them in a paper grocery bag so it would be dark and I tried to stabalize them but I'm sure they got tossed around a bit
Well 7 years later they are fine. They weren't even messed up when I brought them back.. and keep in mind they were very young, tossed around in a plane and car, for 4-5 hours. Its not 10 hours like yours... but I'm sure they were younger then yours. So I just can say that turltes are pretty strong creatures.. if you have kept them healthy, I don't think keeping them in a rubbermaid with some water will hurt them that much.
I've read the alternatives some while ago.. like keeping them in a damp towel.. and I just gotta say it sounds pretty bad. I mean first you are immobilizing them, locking them up in some weird feeling towel, and then interegating them for 10 hours (lol k I'm just making this up). I feel that although this might keep them safe from being bumped around, it sounds pretty cruel. Maybe if you're driving just keep them in a rubbermaid with some water and take it easy driving. No need to do sharp turns or anything