I hope Strapper211 is not considering selling a BMW 2002 M5 to cash in on a new TT. As good as music system gets there is nothing more fun than the feeling you have connected to the road while driving a M5. He may regret that choice. IMHO, always have the newest and best M5 you can own (DynanM5 or Alpina) 1st and then the best music system you can second.
My bias is go for the Brinkmann (less $ than Walker) and keep the M5.
My bias is go for the Brinkmann (less $ than Walker) and keep the M5.