7.5" wide rears for a 451 - about ET 30
7.5" is probably too wide for the fronts though... 6.5" wide ET 30 with 205s offers several tire choices that don't rub.
There is forum member running 17x7 Brabus in front with 215s; I think there was only one tire that worked lol.
Hopefully he'll chime in with that front offset / tire combo.
That member may be me. I have 7.5x17 Brabus wheels on all four corners with Hankook 215/35-17 tires all around. They are the stock tire for the rear of the US spec Brabus. My set up will fit fine with no rubbing or electronic nanny intrusions. I have since added Eibach wheel spacers. Not for clearance, but to get a more flush look in the wheel wells. The front spacers are 20mm and the rear spacers are 30mm.