You don't specify and I can't tell in the first picture if the car if the car is 'pushy' when you are on the brake, rolling or under part throttle?
If it's under braking you're driving in too deep and need to be off the brake at or before the apex.
A rear bar will tighten the car up, not remove the push.
Try lowering the front tire pressures (if it's pushing from the middle off) and/or loosen up the front swaybar. That's the easiest thing to try first.
If you're real serious, loosen up the T bars (springs) and limit your travel using adjustable bump stops. Then tune with shocks and tire pressures.
If it still won't co-opperate from the center (apex) off you'll have to loosen the car up with the gas pedal.
One thing though- I have never done slow speed autocross parking lot racing so take it for what it's worth.... but I did stay at a Holiday Inn one night :rolleyes: