I took a 1" PVC pipe and cut it to around 6" or 8". Once I had this I then used two galvanized straps with galvanized bolts and nuts to mount the PVC pipe horizontally to the mast post. I then used rubber cement to attach marine carpet around the PVC pipe and up the side of the mast post. Finally I drilled a .25" hole through the PVC vertically, between the eye straps and ran a .25" shock cord through it. I tied a stopper knot on the bottom and a bowline on the other end, just short enough that you have to stretch it to go around the PVC piece sticking out out to the port side (PVC sticks out to port side, it's flush on the starboard side of the mast post.) This gives me a nice cushioned area to rest my spin pole on. I'll take picture if anyone cares.

I actually trailer my boat pretty much the same way as said earlier, and I leave my spin pole completely set up (except the spin pole bridles which are quick disconnects ...C2 and Viper style with the knot.) I leave my spin bag on and have reached speeds of 80 mph with it trailing behind my truck. My spin pole bridles with yellow telltales rest inside the bag; I have watched it while driving and it doesn't get affect by the wind. Most of the wind is blocked by the truck.

Just my $.02.

Oh, and I also leave everything rigged that I can, and I stuff all of the excess lines into my big tramp bag. I store it next to my house this way with a top gun cover and it all stays dry underneath.