Jim Eldridge essentially wrote this for us by example:
I have a 1985 Dodge Daytona that has 135,000 miles on it. It runs great. At about 85,000 miles the timing belt broke, stranding my wife. The maintenance schedule says nothing about replacing the belt. Dodge thinks it's OK to wait till it breaks and then replace it; the design is such that it does nothing bad to the engine. However, to my wife, the car broke down and had a "serious engine problem." [Note: the manual actually does suggest replacing the belt at 105,000 miles.]
My friend with a Nissan Maxima just had his 60,000 mile maintenance at the dealer. He had the timing belt replaced, the fuel injectors cleaned, oil change, etc. and a fuel injector replaced. Cost, $850! If he filled out the CR form, he would show no major problems, just routine maintenance.
He then told me he was considering replacing all of his shocks because "it was about time." No Dodge owner would ever consider replacing shocks before the car bounced down the road. All Dodge had to do was recommend the belt change at 60,000 miles to avoid a "serious engine problem."
Will Mast said, “A friend with a Toyota used to brag about how trouble free it was until I showed him all the repairs, including a cracked exhaust valve, that were hidden in his 30,000 mile "maintenance" visits to the dealer.”
The solution is to get far more specific - and perhaps, to be really careful, to find out something about owners' routine maintenance.