my XA coupe (years ago) had 15x8 with 275 50series TA's on it. (they were shit) They hit the inner arch if I really dipped the car hard but it had 1 inch lowering blocks too. I cant remember if they were offset or not. I think they were set positive on track by an inch.
There is a coupe owner or two on this board who may be running the big rims.
I think you can fit 10" rims and 265 or 275 tyres on it with no offset or 10p etc. You are more likely to hit the inner wheel arch than the outer one.
Have you been to a rim seller to test fit???
They should be able to help??
Well done SA pollies (for once). Hoon laws are long overdue to protect car enthusiasts against idiot drivers.