No adjustments needed for the 20" rims easy_rider. RUF also delivers the Rt12 with 20" rims in option but they do say 19" is much better for handling and performance.

I had to test it TB993tt
The car already did 345kph (RUF tested it) and they told me that installing the GT2 front would only improve stability at higher velocity. The car felt amazing to be honest, no lift upfront whatsoever ... and this is still with the stock suspension.

RUF also performs windtunnel tests btw ... they just don't make a big fuzz about it like some others do.