style 351 question

been lurking for awhile in preparation for moving from my X3 to 5series. Found a 2011 535xdrive w/7k on it. It has Sport (not Msport) premium, nav, cold, and all the stuff i want in the color I want. The wheels are style 331 19 inch which I like but dont love. Before I torture the dealer and ask to put the wheels I really love on the car (style 351 from the M sport) I was wondering if anyone has tried this? Are the 351's staggered? cant tell from the bmw website. Is this wise or is the vehicle calibrated for non staggered wheels at the factory?

also a couple questions --1. if I swap out the runflats to the tires i want to run year round (Conti extreme DWS) do I have to return the car with the runflats on at lease end? and 2. I am 20k miles over on my lease return (yes poor planning -- I didnt expect to do this) I have been told that you can negotiate the 0.20/mile down to 0.18 or even 0.16 as a return customer. Any tips on doing this? (other than not letting it happen again!) all thoughts are welcome -- thanks.

The MSport xDrives are non-staggered in the US, but staggered in Europe. The 351M wheel is available for either set-up.

I've never leased a BMW, so I can't help you there.

Thanks -- so the 351's would be a simple swap it seems. Any opinions on whether I should let the dealer do it and over charge me or do it afterwards on my own? Thanks