What size Spacers???

[R2dmax]

I have some MAAS Sagittas that I am refinishing for my car. They are 18x8.5 and 9.5 ET 15 Offset (I know, not quite Stanceworks material). Iam only going to mildly stretch the tires but I plan on the stance being nice. I have an e39 touring. What size spacers do you guys recommend front and rear? I want to bring the wheels out to the edge of the wells.

[SeanDub]

I'm not familiar with the car at all, your best bet is going to be just measuring the space you want to fill and spacing accordingly.

Some people may offer advice but then you have to take into account the camber they are running, how much fender work they have had done etc.