Common Problems with 645CI????

[irvz]

looking to buy an 04 or 05 645CI and was wondering if you guys have any tips or advice on what to look out for. any common problems or concerns I should be aware of?

also, what are the optional packages/equipment that are not standard on all 645's that you would consider a 'must have'..

lastly, (no bias lol) but if you had the choice: MB CLS500 or BMW 645?????

Thanks!!