I disagree. With the new CAN-Bus (controller area network) on newer cars, the amount of self diagnosis is astounding, if you have the tool to interface (mere OBD II scanners are like a ball peen hammer). As for disconnecting an engine mount to change the spark plugs, I don't see that as such a big deal, even working in a driveway. You only need to do it every 100k, anyhow.
Pulling an engine (or drivetrain) to remove the oil pan. Some cars are like that. Sometimes you can get by with lifting the motor only part way out. The books definitely don't always give the easiest procedure.
