I'm wondering if my 2nd hand Clubman S has it.

And, semi-related: does engaging the "Sport" button affect the suspension in any way?

 

The sport button doesn't affect the suspension in any way. Just the throttle mapping and steering weight. (And shift points on the auto.)

Sport suspension was an option on second generation MINIs. I'm not sure how you can tell if you have it or not. If you can see the shocks, they might have a lable on them which says "Sport".

The non sport suspension isn't bad for everyday driving, I don't think I'd notice its absence short of driving on the track, or an autocross. The S has a slightly stiffer suspension that the JustaCooper I think. The sport suspension is a bit stiffer than that and pretty much the same on an S or a JustaCooper. We've had it on all our 2nd gens (Justa, S and JCW), we had to order it as an option in each case.

 

It is my understanding that the S comes stock with the standard suspension, the only difference from the non-S being a stiffer rear swaybar.

 

As indicated, the sport suspension was an option that had to be selected and added to an S. There were lots of S models bought without the package because folks figured they could go aftermarket to achieve the same end result for a price similar to or less than what MINI wanted for the package.

If I remember right, one of the items included in the package was the 17-inch wheels. So if you have 16-inch wheels, I don't think you have the sport suspension. Of course, you could upgrade the wheels to 17-inch without getting the sport suspension package.

 

The sport package and the sport suspension were separate options, one does not imply the other. Our S had 16" wheels and the sport suspension.

 

Hee! My Cooper has the sport suspension option and the stock 15" wheels!