The application for that wheel is for an M5. Remember M5 suspensions are slightly different that other E60's where wheel fitment is concerned. On a non sport suspension you might be ok, but if they rub, take them off, put your old wheels back on and get some spacers.

 

That should fit. I ran a set that had an offset of 20. 18 is only 2mm further out to the fender. Mine were 19's but your tire sidewall is smaller on the 20's. I doubt you will have an issue.

Cheers

 

As you said. don't think that 2mm will make an issue.
about the tires don't think that gonna issue with them
check out this link
BMW E60 5 Series Rides on F10 M5 Replica Wheels - BMW Power

 

I've personally never heard of that brand, but be very weary even if they look like m6 wheels, they can be extremly cheap cast wheels that will bend. Hell I have miro's and I've had 2 completely bend on me.

 

I've finally chose to get 19inch in my car,and her's the result