Should be similar but not the same as.
If you try it be sure to run two air hoses and two schrader valves. If you run both bags off one filler valve you will have installed a pro-roll-bar as opposed to the anti-roll-bar effect you want.
I would _imagine_ for Auto-X the worst you will do popping a bag is slaughter a few cones. Apexing on a fast road racing course losing a drag bag might get the car to roll all the way over, what we call an 'undesirable outcome' in the medical field. I suppose you could roll a car on an Auto-X course, dunno.
Be advised also the factory shocks are reasonably well matched to the sprigns, as in enough pressure in the dragbags may put the spring/shock unit out of balance on the rear axle, and also enough pressure in the bags will put the spring/bag combo on the rear axle out of balance with the springs on the front axle.
You might scroll down this section some, there was a thread started last night by someone unhappy with drag bags, you might be able to buy his cheap.