Rear steer used to be popular but nobody uses it today because the links are so long. On the CRC 3.2 or the old Speedmerchant you could get a fair amount of movement with such short links and a reasonable number of shims, but you would need 5-10mm of shims to get anything worth talking about on a modern car.

If you do the math for the 0.5mm of shims installed in Kevin's car, the deflection of the rear pod even with the chassis fully compressed is on the order of 0.02 degrees, if that. (assumed 60mm links, 2mm of movement, 40mm from the pivot) that is basically zero. This is not a speed secret that we all need to go emulate right now.