Harvster's DIY Plastic Wood Repair:

The broken edge of the plastic will look
    whitish,  because of light reflection.  You need to sand the edge
    smooth.  To do this, get 1500 and 2000 grain wet sandpaper.  You can get
    these at auto shops like Kragens or Pep boys.  You will also need
    Meguiars # 17.  You should have this and Meguiars # 10 for you rear
    window anyway.  
    
    Soak the sandpaper in water for an hour.  Remove the radio(carefull this
    time).  As a rule of thumb,  always tape up around where you are
    working.  Now sand the cracked area smooth with the 1500 sandpaper. Keep
    it wet.  Sand until you get all the white edge off and you can't see the
    edge.  Now sand with the 2000 sandpaper.  These are both so fine that it
    will take some time to sand the edge down.  The plastic will now be
    smooth with fine scratches around the area you sanded.  
    
    Now,  apply Meguiars #17.  Pollish the area and surrounding area about
    20 times rubbing hard.  This will get all the fine scratches out.  Wipe
    off the Meguiars.  You should not be able to see the edge of the
    plastic.  If you are satisfied with the way it looks,  good job.
    
    If it is obvious that the plastic came off and you don't like the way it
    looks here is what you do to finish it off. 
    
    If you have a BMW paint touch up kit,  it comes with a tube of clear
    lacquer.  If you don't have the kit,  I imagine any clear lacquer will
    do.  Shake up the lacquer and apply it to the area with a toothpick, 
    spreading it so it is slightly  raised above the surface of the
    plastic.  Put an old credit card under it so you don't drip it on the
    lower console.  Let this dry for several days.  You will be able to see
    the edge of where the lacquer is with incident light,  but the lacquer
    has the same light refraction as the acrylic,  so it looks just like the
    plastic.  Now,  you need some Goofoff.  You can get this at any hardware
    store and it is great for removing the airbag stickers on your visors.  
    
    Everyday, take a Q-tip, dip it in Goofoff,  and gently rub the lacquer
    surface.  Don't do it more than once a day,  as the Goofoff will
    completely remove the lacquer.  This process dissolves a tiny bit of
    lacquer from the high point each day.  After several days,  the lacquer
    surface will perfectly match the plastic and you will not be able to
    tell it is any different.  Now polish the entire console with Mequiars
    17.    You have saved yourself $200 ,  about 6 hours of frustrating
    work(removing the center console) and possibly many other damaged
    leather ,  vinyl , plastic parts not to mention cut hands,  broken
    switches and wires and blown fuses. 
    
    If you have any questions or run into problem,  email me.  I spent many
    months perfecting this process.  I had a tiny crack in the plastic edge
    of the radio surround caused by cleaning some dried polish out with a
    butter knife.  I'm sure no one would ever have noticed it, but to me, 
    it was like the biggest eyesore in the world.  That what being a Z3
    owner is like.  Compulsive anal about the car.

Esmerelda's Home Page