You would have had to know how the internals work? Why? I often hear people nostalgically talking about how it was better in the olden days when people could f

You would have had to know how the internals work? Why? I often hear people nostalgically talking about how it was better in the olden days when people could fix/tweak their engines as they wished. If you lift the bonnet of my car it's a sheet of plastic and a few colour-coordinated filler lids so that I can top-up fluids. No hackability whatsoever.