On the non-M E46, it will be called SSG, not SMG. It is not available in the US. It works the same way as SMG II, but:
a. Is made by a different manufacturer
b. Has 5 forward gears instead of 6
c. Has less "modes" than SMG II
d. Shifts slower than SMG II
If BMW does release it in the US, I doubt it will be before the 2004 model year. BMW NA has typically been very conservative when it comes to bringing items like this to the US. It is very much a marketing move, and I personally think they will decide the average E46 owner probably isn't "ready" for it yet.
a. Is made by a different manufacturer
b. Has 5 forward gears instead of 6
c. Has less "modes" than SMG II
d. Shifts slower than SMG II
If BMW does release it in the US, I doubt it will be before the 2004 model year. BMW NA has typically been very conservative when it comes to bringing items like this to the US. It is very much a marketing move, and I personally think they will decide the average E46 owner probably isn't "ready" for it yet.