If you are able to purchase a newer model, avoid the 04 model. This is the 1st year that the 645 was made. There were a lot of bugs to worry about. Not all 04's have problems, but try for an 05 or newer if possible. Every trip to the BMW dealer will probably cost around 800.00 or more. You are getting a fairly good deal, just informing you about repair expenses on a BMW. I would search the forum for common repair cost.