mines a liberty not a rex, but I just run full soft for the road.
track depends on tires but usually nearly full hard in the rear and about halfway in the front. On better tires I can soften the rear a little, but honestly it doesnt make a huge difference to laptimes having it on different settings.

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2001 Liberty B4
12.7 @ 178kph 1/4 mile
59.1 Short Track @ barbagallo (Federal 595s)
58.2 Short Track @ barbagallo (Toyo R888s)