I am wondering if anyone has come up with a device to brace a vertical action when transporting it in your vehicle. I know the piano supply companies sell devices for this purpose. It just seems to me that one could make their own braces in some way. I have some ideas of how it could be done. I just wondered if others had come up with an efficient way of doing this. Thanks all for your help.

I just do it hammer faces down. If it bothers you, clamp some sticks to the brackets so that it rests on them, rather than any parts of the action.

I made up a carring box out of 1/8" plywood atached to a bottom board with the same hardware that is found in the piano.And a plywood cover with foam blocking to suport the action parts from shock.
I only use this on actions that are very fragile, takes two people to cary it.The best way is face down on the hammers if going across town.The action holders made from metal tubing is also a good way to go.They have a clamp at each end.

I've had to get creative since I made the huge mistake of trading my pickup truck (with a huge fiberglass cap) for a smaller SUV. I take a heavy piano mover's quilt, carefully cover the action, and carry it in the back seat, action standing up, same as when it's in the piano. It's a good fit, it's protected, so far no problems. If there is too much wiggle room, I use another quilt to keep it steady.

Ditto with Sam, except I don't cover the action, I just brace it on both sides with moving blankets. Sometimes I'll recline the front passenger seat for extra bracing. Grand actions fit on my back seat braced with moving blankets as well. I have a Toyota Matrix.