Here let me clear this up.
Bryan is absolutely correct, as he usually is
The 1st generation e46's were equipped with the m52tu engine and were either a 323 or 328
the 328 having the m52tu b28 pro dates 6/98 to 6/00
the 323 having the m52tu b25 pro dates 6/98 to 9/00
The TU in the engine designation stands for technically updated and indicates that the engine did have dual vanos (among other improvements)
Then later the m54 engine was introduced with the 325i and the 330i
the m54 b30 from 6/00
the m54 b25 from 9/00
All of these engines were and are dual vanos.
Now the confusion of the e46m3 being the only dual vanos e46 is incorrect, however ithe m3 was (i believe) the 1st model to ever get dual vanos in Germany as an e36 and also on the race circuits.
Hope this info helps to clear some stuff up.
P.S If Storme is from the UK then that is prob why his engine doesnt have dual vanos, obviously non-US cars have different spec motors. All the info I have posted is accurate for US spec cars only.