Um, well at 180K a lot of "maintenance you will have to do" depends mightily on what's already been done.
I would check the wiki for info.
I would also contact a BMW specialist mechanic and arrange a thorough inspection of the car, unless you are knowledgeable enough to do one yourself.
For starters, you could ask when the last time the following services were done:
- Cooling system (complete: radiator, thermostat, water pump, expansion tank)
- Fuel filter
- Fluid change (engine oil, transmission fluid (AT or MT), differential fluid)
- Braked components (disks, pads, fluid)
- Control arms, bushings, struts, rear shocks
If you get a "Uh, uh..." for any of the above, ask for service records. Poor service coupled with this mileage is not going to end well for the purchaser.
I would allow about $2,000 in annual maintenance costs for the car.
“Character is doing the right thing when nobody’s looking. There are too many people who think that the only thing that’s right is to get by, and the only thing that’s wrong is to get caught.”
- J.C. Watts Jr.