I also have a 98 328i, and it developed that problem within a week after i bought it (had about 50,000 miles). Fortunatley, the tail light and brake light circuit problems are really common so you can find the info from a google search.
[smashed in front bumper] [lethargic 4 speed automatic] [custom pre vandalized paint job] [factory 15" alloys]
<span style='font-family:Arial'> Everybody loves foglights! <span style='color:red'>EVERYBODY </span> </span>