@Firstsportscarat40 I'm planning to get Enkei RPF1 or PF01 in 18x9 and 255/40-18 unless I go staggered. Staggered could be 295 on 10.5 wheels at back.
30mm offset is somewhat aggressive, and possibly not within the autocrossing rules for the class you wanted to race in, but it's probably the maximum that would fit up front (with 9 inch wheels and 255s) according to
@Mad Hungarian. If you want to stick with rules, get the maximum offset and width allowed for the target class.
I hope to track the car for fun high performance driving days, and probably won't competitively autocross, so don't care about rules, per se.
Regarding stagger, any of the Model 3s could benefit given the high rear wheel torque, but on the other hand, the dual motor are near 50/50 weight distribution front to back, so square wheels could be ok. BMW 3 series also has 50/50 and sometimes use square (same width front and back) on the race track, and those are probably mostly RWD.
Having more rubber/grip/roll stiffness at back generally reduces oversteer. Having relatively more rubber/grip/roll stiffness at front generally reduces understeer.
