Imho a PPI is different from a service .. its more intense .. we look for what is wrong and report it so things like air vents with broken slats , cigar lighter not staying in etc .
Air vent i would actually say on a service so not a good example ... but im trying
When serviceing a car i make a judgement on what will last till the next service or beyond .. on a PPI i will report these items reguardless and then advise on expected lifetime ... its not my judgement on what to report anymore .. scareing the customer on a ppi is what is required .
A service is to tell the customer what I think needs doing either now or at next service .. im not going to make a huge list of things that dont need attention but have some degree of wear ..
A ppi i will report everything that i consider worn .. i will then explain that ( often very long ) list to the customer and what actually needs doing ..
Basically im reporting everything i see thats not upto brand new spec .
A ppi from me will often be a long one but the actual work needed will be a lot less .. inform everything miss nothing and explain well !
Hopefully this makes sense !