I have a 99 323 and the same thing happened to me (albeit a little later in the car's life).
It was an incredibly frustrating experience, as I also had two spark plugs go bad, the camshaft positioning sensor go bad, almost all at the same time, but they masked one another. It took 5 trips to my mechanic to get it fixed!!!
I finally relented, and replaced all 6 coils and spark plugs just so that I wouldn't keep having problems...
I feel your pain, man.
<span style='font-size:12pt;line-height:100%'><span style='color:blue'>I don't drive fast,</span> <span style='color:red'>I FLY LOW</span></span>