Confused someone set me straight?

[harry007]

I currently have 343m black 20" alloys on my vehicle, with 12mm front and 10mm rear spacers. Its a good set up and also have h&r lowering springs. And extended nuts.

So.... I fancy a new set of alloys. Ive been looking at the BBS CI-R, which I will get redone in satin black.

My question, what is right set up?

20 x 9.5 ET25 or 20 x 9.0 ET35 rear?
20 x 10.5 rear ET35.

Do I need spacers still? Can I still use my extended wheels nuts. Some sites are suggesting I will need spacers for the front 20 x 9.5 ET25? I've simply over thinked it, and confused my self. Someone please clarify what needs to be done to have the BBS CI-R fitted with good stance, I will be using existing tyres. Thanks H

[M6-Coupe]

20 x 9.5 ET 25 front with no spacer. The OEM 343M (M5 black) has 34 mm offset so these setup is already 9 mm out
20 x 10.5 ET 35 rear with 10 or 12 mm spacer will be aggressive setup, since it's almost the same offset of your 343M (34 mm).

343M (M5):
Front: ALLOY RIM FORGED 9JX20 ET:32 ; 36112283999
Rear: ALLOY RIM FORGED 10JX20 ET:34 ; 36112283401

Front: ALLOY RIM FORGED 9JX20 ET:34 ; 36112284599
Color: matt black
Rear: ALLOY RIM FORGED 10JX20 ET:34 ; 36112284602
Color: matt black
http://www.realoem.com/bmw/enUS/show...diagId=36_1643

You can also check this website and play with numbers to find your desired setup
https://www.rimsntires.com/specspro.jsp

[harry007]

So basically if I choose the bbs ci-r front wheel with 20 x 9.0 ET25 front and rear 20 x 10.5 ET35....

I should use a front 12mm spacers to level up with the rear as 0.5" = 12mm wider @ 10.5"? Than original

As the rear is wider without a spacer, can I still use the extended lug nuts?

[M6-Coupe]

There is no relation between the width of rim and offset.
12mm spacer is not because of 0.5". As I explained the new rim has almost the same offset of OEM and if you have 10mm or 12mm spacer and happy with the look, you can use the same spacers with new setup (for rear).
The front is already have less offset so you are good to go with no spacer