Do not completely disagree and most of this stuff can be done on your own however some can't like putting the car on lift to thoroughly look and check for leaks-electrical need the factory software to run a system check, just because there is no CLE does not mean there are not sensors or other electrical problems. I was looking at G a few years back, all checked out however when i drove it and hit the throttle hard a few times the dash lit up with all sorts of errors-none were detected in the PPI which did not check the software/electrical systems. Great car everything else was solid however i passed could have been a simple sensor or something far worse.Totally agree with jj33low, PPIs are over hyped. Not that they are completely useless but in my opinion just not worth the cost, especially if who's doing it is not intimately familiar with the make/model. There are stories on this forum of useless PPIs, where major issues are missed, even when done at the dealership.
Get a bunch of pictures and video, and ask a ton of questions. You'll be fine.