Not sure if I understood ( ants_oz) but sounds like he said spacers is the wrong way to do it? Can say I agree or disagree is all about preference .
How ever if your going passed 20mm I highly recommend DRA spacers that bolt to hub . Longer studs can be dangerous on heavy cars like ours .
Just in case you or anyone is wondering from e53's to F15's in our group are using spacers , specially if you want to flush out the wheels with the fenders .
Unless you go custom, it will be hard to find wheels to meet those needs.
Here is one example , owner is a forum member as well .
4.8is 25/30 mm spacers

Here is our group , pics from Bimmerfest yesterday