Change your own air filter. Easy job (normally) and much cheaper than paying a shop to do it. You can easily save 50% on the filter alone, then add their 10 minutes of labor at $65/hour to your savings. A late model Honda Accord has a $35 air filter, so you can easily hang on to a $20 bill by replacing it yourself.
Transmission Flush, and Power Steering Flush is a good idea every 2 years if you keep your cars longer than about 4-5 years.
Brake Fluid Flush *should* be done annually. Brake Fluid accumulates moisture, so replacing the brake fluid will extend the life of the metal and rubber brake components.
Extended 50,000 mile oil changes? Buyer beware! Your oil filter definitely will not filter for 50,000 miles. Ideally, you wouldn't run a filter much more than 5K. After that, a significant portion of the oil is simply bypassed through the filter, and not "filtered."
An engine flush to a late model car can actually be dangerous. Basically, they circulate kerosene through the engine for 2-3 minutes, and then drain it out with your oil. With the low tolerances of a late model engine, if there's sludge in there, I'd rather it stay put than dislodged and circulating throughout. If you don't have an oil flow problem, it's basically a waste. Real surprised that a quart of kerosene and 5 extra minutes costs $90.
