Wow, even a package car mechanic is saying UPS doesn't care? As an Automotive Supervisor I take offence to this. I look at my fleet as, would I want to have my wife and kids following this car on the road? If I cannot truthfully answer yes, then the car does not run. Mechanics do not take heat for roadcalls, as long as there is not a trend or pattern that develops. As far as a driver is concerned, If you do not feel safe driving the vehicle, do not drive it, but at the very least know what the Out of service Requirements are. I have never heard of a driver getting in trouble for refusing to drive a car for legitimate concerns. If my mechanics are not performing and keeping the cars running in a safe fashion, They will either correct the trend or they will not be working on the cars. Ultimately I have the responsibility for the safe operation of 300 cars, and I have a crew of fantastic mechanics that do not take short cuts.