I was winching out a center pivot system with my Rubicon and had to put it in reverse to hold it. The brakes would not lock the wheels while winching. I have a 2.5 Warn on an '03 Rubi.

 

So the Rubi was sitting still while you were pulling something else? Tie the quad off to something next time with a rope or cable. A lot easier.

 

I carry two tree straps and a few shackles. Whenever possible, I'll tie off to a fixed object by running one of the straps through the rear tow hook (Cabelas) on my machine and then around the fixed object back to the machine. Might could also block the wheels if there wasn't a fixed object around handy.

 

I have a multi mount for my winch, works great. Can winch from the front or back. I bought an 1" ball mount insert and put a shackle on it. So I can strap the quad no matter which way I'm facing. I carry a 15' and 20' tow strap. A tree or fixed object is best to tie off to. But even another quad is usually enough weight to hold you in place. Just be creative if you have to.

Good Luck