M refers to music and the number following is the order of cues, with M1 being first cue of music you will hear in a film and M9, for example, being the last clip of music in the film.
2009 e92 M3 Individual Laguna Seca Blue
|Black Novillo|DCT|19"rims|Carbon Leather|Premium|Tech.|Heated Seats|Prem. Sound|iPod|
Mods: |Electronic Performance Steering Wheel|ZCP CF Spoiler|ZCP CF Spliters|ZCP CF Mirrors|Edition Front Grilles|Edition Side Grilles|BMW Performance Brake Handle|3D Design Pedals| Style Rumore Exhaust|H&R Springs|LCI Tails|Challenge CF Door Panels|