How far out of warranty are you? That's a known issue for some early model E9x vehicles. Basically the back of the seat clip, female portion, rubs against the console wearing away the paint. Later models have a peice of material atttached to the back of the seat belt clip. You can get spray interior paint to cover that, remove the console etc.. DIY should be in that section for console removal but I'd see if they would good will fix that first based on your warranty poistion and if you are the original owner.
08 E90 335i Monaco Blue Gray Dakota ZPP ZSP Heated Seats CA Step w/Paddles iPod