Originally Posted by Radio Active

Interesting, so it's basically doing the job of side springs for side-to-side resistance and tweak adjustments. I guess there is more slop in that arrangement than a side-spring set-up would have, otherwise I could see it working on a modern pivot ball car.

One of my favourite pan car set-ups was the one used on the Tamiya F102 and Group C cars. It's similar to what you describe. T-bar connected to the chassis (essentially) but there is an o-ring instead of a washer in there. Tightening the screw that went through the T-bar and the o-ring would put more pressure on the o-ring and reduce side-to-side movement. I always enjoyed tuning my car with nothing more than a Phillip's head screw-driver in under 5 minutes.