If it's time to tune up your car then what about your body?

I just had a patient say something interesting to me.  The essence was that people are keeping their cars longer so they need more mechanical work.

There is no machine more complex than the human body. At that body's core is the spinal cord and nervous system.  

When you think about it, you only keep a car ten to fourteen years and you keep this body for seventy five to ninety.  

Isn't it time for a tune-up?