Did they set the engine up on a scope? Does the engine miss? Will it pass emissions (if required?). I let my cap/rotor/plugs go for over 70K on a new truck. I know about changing these parts every 30k as per manual service. But don't you think this is a little secret about "moving parts" in the service department, a little over done?
I recently changed the parts (cap/rotor/plugs) because I felt a little miss at idle. I kept passing emission tests with these high milage parts. Granted, the parts would have lasted the life of the car, but I am more anal with other areas.
I dumped the rear end fluid at 500 miles. Then every other time with an oil change. I changed the air cleaner every 10/15K. Change the oil and filter every 3/5k. Change both the trans fluid and pack front wheel bearings and replace new seals at 15k intervals.
Kind of makes a tune-up the last thing to tackle.
You can tell if they pulled the cap off by checking to see if they touched it at all. If there is dust all around the cap, and no finger marks, then yes, they didn't look to see how worn the inside was. I would question the drivability tech they have there.
At times, you really don't need to change (some) parts if all is well.
