As per a different thread, I decided to remove the 15mm rear swaybar and replace it with a 12mm one. Today's trackday started off with a moderate shower which drenched the track. The rear felt more stable than with the 15mm rear bar. As the day progressed the track dried and I found I could drive the car much harder into a corner and didn't have to lift nearly as much as with the larger bar. The RB Hollow race bar didn't seem to cause the car to push either. Thanks for the tuning advice.