I have always wondered what maintenance regimen would be reasonable for older cars with higher milage in order to keep it in good condition and at the same time keep cost to a minimum. I have a 91 560SEL with 145,000 miles on it. I have owned it for more than 3 years and it is running good. I change my oil (DIY) regularly, and visits my mechanic at least once a year for maintenance. Within the 3 year span I have replaced the radiator, and water pump. any inputs would be great.