H-stock AutoX. Front or rear swaybar?

[CoryM]

Hey guys.

Winter AutoX series is starting soon which means the Yaris will be destroying cones again (yay!). Assuming I haven't misread the rules, I can either upgrade my front bar OR add a rear bar and stay Stock.

I am having a hard time deciding which will be more beneficial. It seems as if most of the roll comes from the back, but in most cars a rear bar will create more oversteer. That being said, the only oversteer I really mind in this car is the "lift-off oversteer" and I wonder if the bar in the back will affect that or not. With a bar in the back, do you notice much less roll from the rear, or just less flex in the torsion beam if you get what I am asking? I think the flex in the torsion beam adds to the "lift-off oversteer". I think it must toe-out when it flexes.

To give an idea of what I am trying to reduce watch here:
http://www.youtube.com/watch?v=hl0pDNP_jb0

At the 50sec mark I do a slight wiggle which starts to upset the car, then decell and left around the cones. That one was pretty mild as it was my first run. I had 3 runs where I was rather sideways into the stop box. I realize this is probably a worst case scenario (or a good example of a Scandinavian flick ) but there have been a few other courses that I run into this so it would be nice to tune it out.

Anyhow, summary: Front or rear bar and why?

Thanks for any input.

PS: Only mods are 205/50r15 RA1s, -2° camber front.
PPS: I know I take too long to get back on the gas when sideways. My reflex is still from RWD so I don't go for the gas until my logical brain takes over. ;)