I was always told to keep the rear wheels as neutral (close to 0.0°) as possible, in most cars. -0.1° of Toe is really nothing, and if you add a click, you generally end up with something like 0.5°, so you go with -0.1° because it's closest to 0.0°.
That said, if you are qualifying, adding -0.5 to -1.5° of rear toe CAN help the car rotate, especially in tight, low speed, corners like Bathurst..... for a lap or two...
Are there other ways to achieve the same thing? Probably, but connecting the Audi's rear-ARB made the car too unstable over the fast corners of the mountain, so I went with the toe adjustment FOR QUALIFYING-ONLY, and picked up a little bit of speed.
Don't confuse this for me liking negative toe. I don't. I hate it, and it makes the car super unstable, especially as the tyres wear off... but it CAN be faster, if you're talented enough to hold on to it. I am not. Negative toe can go fuck itself....
...unless I'm qualifying the Audi at Bathurst....
Maybe, because of how naturally understeer-y the Porsche RSR is, the rear toe isn't enough to destabilize it? But like I said, if it's only -0.1°, it really shouldn't be enough to make a difference anyways. It's basically neutral, and you're just not ADDING any understeer, like you would by making it positive.
