As for hanging planes vertically...I've done it for 3-4 years now, and got the idea form my uncle who's been doing it for 30+. Doesn't seem to have caused either of us any problems. *shrug*

Here's an idea I came up with 2 years ago for the wife's van, and have duplicated in my new Kia Sportage:

Go to any hardware/home goods store, and pick up some shower rods. I've found the screw-type (the ones where you screw in or out the one end to set the length) work a bit better, but the spring-type will work as well. You'll need at least 4 of them.

Then run to the plumbing section, and get some sort of pipe hangers. They're shaped like a J usually, though other types will work. http://www.lowes.com/lowes/lkn?actio...5216&lpagenone is an example at Lowe's. You'll want one of these per shower-rod for each "level" of rack you plan to build. (So, if you want to have 2 levels, you'll need 8 of them...hope that made sense)

You'll then want some hose clamps...two for each pipe hanger.

And finally, some PVC pipe to use as the "racks" themselves.

Using the hose-clamps, attach the pipe-hangers to the shower-rods.

Then, place the rods in the SUV/Van running floor to ceiling, using whatever adjustment method the rods have to make sure they're good and sturdy.

Finally, place the PVC in the pipe hangers, running side to side (horizontally in the vehicle, in other words). Have one in the rear, another up front, and others in the middle if needed, depending on plane size/weight.

Poof. Airplane transport rack system. It's cheap, requires no more tools than a screwdriver, and can be easily and quickly removed from the vehicle, without modifying the interior in any way. You can slide large gassers under the bottom rack, and then run other planes on the racks themselves. With a little creativity and some extra rods, you can even have a wing rack on one side.

Using this method, I can transport:

1/3rd scale Pitts Bulldog
Giant Aeromaster
.40 sized Super stick
GWS Slow Stick
Funtana .90

All in a Kia Sportage. Granted, there's no room for a passenger in that scenario, but that's a whole bunch of airplane in such a small vehicle.

Here's a quick and dirty drawing of the concept (VERY quick and dirty....don't laugh *heh*). I'll drag my system out and install it this afternoon when I get home from work, and post some pictures.