Does anyone know the offset and bolt specs for a 2003 xkr with 20" wheels? Front 20x9 Rear 20x10

Is there a range of offset that would fit without issues?

I need to replace my Montreals with some aftermarket wheels.

Also, would a 10.5 inch width rear wheel with the right offset pose
any problems?

I've searched the forum for this info with no luck.

Thanks for your help, everyone.... Ed.