There is no doubt that BMW is a market leader, since offering free maintenance, several manufacturers have followed BMW's lead.  Obvisouly, free maintenance for 4 years or 50,000 miles is a good deal, and even we would not agrue.  However, whether you consider your vehicle to be an asset or a necessary fixed expenditure determines whether replying soley upon factory maintenance is a good choice for you.  Based upon tested failure rates, vehicle components are designed to last for as long as the manufacturer's warranty applies. Repair costs sky rocket and you start looking for another new car! It's just good marketing for the fixed expenditure consumer.  For those looking for an asset and choose to look past this wonderful marketing campaign. . . consider, BMW's mileage based maintenance recommendations prior to the Free Scheduled Maintenance promotion.

• Automatic transmission fluid (ATF) and filter change, 15,000 miles
• Manual gearbox and differential oil change, 30,000 miles   
• Spark plugs, air filter, and fuel filters every 30,000 miles
• Annual brake fluid change,
• Biennially coolant change,
• Every three months engine oil and/or service or an inspection

Current BMW's maintenance recommendations, Free Scheduled Maintenance promotion:

• 15,000 miles  Engine oil
• Biennial Brake fluid
• Quadrenniall Coolant Change
• Transmission Oil – NEVER, now BMW says they DO NOT need to be changed- “lifetime fill".        

ZF the manufacturer of some BMW transmissions states: "It is recommended, in the event of severe operating conditions, such as: -frequent highway driving in top speed range, -offensive, sporty driving style, -frequent trailer operation, being above average, oil purification (oil change) on automatic transmission is recommended between 80,000 km and 120,000 km, or 8 years, depending on the load."

Nevertheless, BMW states, "BMW does NOT support technician rebuilding of its transmissions, only limited repair and service, for example seals, gaskets, and sensors. Therefore, only limited transmission service information can be found at any BMW-authorized source. . ." (BMW technical information system website)

SERVICE ISSUES

Now, as a result, you will get a different answer from every person you ask about BMW maintenance. At 100,000 miles one common reason for BMW drivability problems, fouled spark plugs, dirty air filter and fuel filter. Lack of Maintenance! While there have been several advances in electronics, fuel economy, etc. nothing replaces practical THOROUGH routine maintenance for asset protection. Consider that BMW still makes parts for that 1970's 3-Series on the road next to you.

Caveat emptor !