[mechanic]

Used to be the practice when I worked for Ford that we gave the customer the old parts in a plastic bag, 1972/3 so that may have changed.
Digital cameras are a mans best friend these days.
One of the worst ripoffs I've seen was oil filters, remove clean and refit, charge for new filter.
None of this stuff is particular to Ford I can assure you.
Don't make the mistake of thinking all businesses are above board. From what I've heard from reliable sources one of the worst is computer repair or warranty work, you get your computer repaired but that doesn't mean it's had new parts.

Another thing I haven't seen for years is the Gilbarco bloke checking the fuel bowsers for accuracy.