It's a Combination of Alcantar and Black Cloth Interior. It may be that it's a euro import to the states as over here leather is only an option on most BMW's (in fact so is alcantar) - except the 5's and 7's (however the e39 came with cloth as standard - mine had the £800 leather option).
You seem to get a lot of our "Options" as "Standard" over there!
Also it clearly has a ///M steering wheel and the carbon is an option over here on all BMW's but comes as standard on the "Sport", models.
It's definetly not a custom job cos that's exactly what I'd expect a 3series sport to look like inside - or an SE with the ///M steering wheel and carbon, alcantar options.