1. Low/Empty Fuel: Allowing your BMW to run out of fuel will probably result in failure of the pump. The fuel pump is in the fuel tank, and the electric motor is cooled by contact with the fuel. Running the pump without fuel in the tank frequently damages the pump, requiring replacement immediately, or in the near future.

2.  Damage From Overheating: BMWs have aluminum heads, which are susceptible to damage from overheating. If the temperature gauge rises rapidly, or the temperature warning illuminates, pull over as soon as safety allows, and have the vehicle towed to your repair shop. Driving a little further, to avoid being inconvenienced, can easily add $2,000 to your repair bill (for a 6 cylinder)!
3.  Brake Wear: Sure, it seem like your brakes don't last as long as they should? Talking on a cell phone while driving is one cause of premature brake replacement. On the freeway, watch the vehicles ahead for brake lights repeatedly and without apparent reason, or sometimes continuously on. When you see one, you'll also probably find the driver talking on the phone!
4.  Fog Lights Easily Broken: The low placement of the fog lights frequently results in breakage from flying debris. Several companies sell clear thick self-adhesive plastic to cover the lens, protecting it from damage.
5. Earlier Engines (M10, M20, M30) Have More Service: The early 4 and 6 cylinder engines require a valve adjustment at each inspection service. The 1984 – 1991 325s, 1982 – 1986 528s and 1989 –1990 525s have a timing belt which must be replaced every 4 years or 60,000 miles. Ignoring belt replacement may result in a repair bill which exceeds the market value of these vehicles.
6. “///M” in the Model stands for Money
7. The “M” models are high performance and relatively low volume. The impact of this is that engineering costs are spread over fewer units and parts availability is more limited. The early “M” engines (S14, S88, S38) were hand built and very complex. A basic rebuild on a 4 cylinder S14 engine (M3 1988-1991) will run in the $7,500-$8,500 range.
8. The big 6 cylinder motors are proportionally more. These vehicles also have some combination of unique suspension, brake, transmission, drive line, body and interior parts. They are very rewarding to drive, but are probably not a good choice if you’re on a budget.
9. Cooling System Failures: Several of the components in BMW cooling systems are made wholly or partially of plastic. Over time, the plastic becomes brittle and fails due to vibration, system pressure, or a combination of these. The most notable components are the radiator and coolant tank. Also, many of the 6 cylinder engines (91-99) came with a plastic thermostat housing that is prone to failure & should be replaced with an aluminum component.

10. Light Bulbs & Failure Circuitry: BMWs have circuitry which monitors current flow through the light bulbs to tell you if a bulb has failed. The newer vehicles seem sensitive to the electrical resistance of the bulbs, sometimes giving erroneous failure warnings when non-German bulbs are installed.. Remember: service is what makes a BMW...

   11. BEWARE a CARFAX report on a BMW is a waste of money! If you buy or plan to buy a used car, you won't have chance to check the service history. BMW Delears are prohibide to show this information.  CARFAX Report would say nothing about services performed at a BMW Dealership.