Leadfoot,
That is a hard one to answer for certain. I know of two people who have did it and one had no problems and the other had his tonneau cover torn up. I think the one that had no problems had a brand new one and the snaps were really tight. He also stopped every few miles or at each rest stop and checked it. The other one was an older one and I think the snaps weren't quite as tight, but he paid no attention until he saw something fly off and up into the air. So if your snaps are tight and you check it every so often you could probably get by ok.
Ron
