I want to know what offset and setup runs best for a set of BBS RS wheels.
I've seen so many nice pictures but no fitment specs.

If someone can give me a general idea it would be greatly appreciated.

Thanks!

 

Real BBS Super RS wheels only come in 19" sizes and 5 bolt pattern so no it would not fit the MINI.
see
http://www.bbs-usa.com/road-wheels-d...m?CLID=58&WF=7

Fake "knock off" wheels that look similar to the RS do come in 17" sizes to fit.
Like this-
http://venturamotorsports.bigcartel....r-silver-5x120
$650 for set of 4, for 17x7.5 or 17x8.5" et35mm in Hypersilver

Assuming that you have stock suspension then-
17x7.5 et35mm fits the MINI and sticks out 13mm or 0.5" more than stock
17x8.5 et35mm sticks out 23mm or 0.9" more than stock
Both fitments have enough clearance for brakes and suspension parts.
Both wheel sizes will work with stock suspension and the 17x8.5 wheel can take wider tires like 235/40-17 or 245/40-17 but wide wheels and tires can weigh more.

If you are lowering your suspension then wider wheels or taller than stock tire sizes can risk rubbing. Use tires no larger than OEM 24.3" to be safe.

 

Can you provide a little more specifics about what wheels you are looking at because as minihune stated the RS wheels are a 5 bolt rather than 4 bolt.
Are you planning some type of adapter?
What diameter wheels do you plan?
Is you car stock ride height?

 

Why are we talking about Super RSs? OP only mentioned RS which are readily available in 15", 16" and 17" sizes.

Not true RSs where produced in 4x100. They aren't as common as the 5 bolt variations but they exist.

Here's an example: http://www.memoryfab.com/wheels/used/20120102173532

 

BBS RS wheels are no longer being made.

See
http://swerbn.articlealley.com/bbs-w...y-2087523.html
The RS wheel is the BBS classic in road wheels. It was the first 3-piece wheel on the market and was introduced in 1983. The RS wheel was produced up until 1995.

If you are considering a used set of BBS RS then what size are you looking at. There were many sizes made over the years.

As mentioned new wheels can be copies of the RS when the price is about $450-600 a set.

 

Guess the OP needs to clarify further.