Part of the reason I like my mechs and pilots setting to be a biohorror nightmare world which leans heavily into unpleasant bodily fluid exchange and physical exploitation of psychological damage comes from my past experience with USA muscle cars. And I know some of you are thinking "but that's just Megas XLR," but it's really not. The thing about being up close and personal with an older car (and this applies to any machine, but old cars are an easier place to find this) is how it conveys in the most visceral manner an overlap between human and machine.
When you're connected to one of these aging vehicles, you're forced to recognize the way it works, and incapable of disconnecting that knowledge from the physical inhabitation of the machine. It breathes. You can see how it breathes, because if you take off the air filter you can physically move the lever that opens and closes the throttle plate and operates the valve for the fuel jets which together determine how much air and fuel are mixed and pulled into the engine.
You can reach into the heart of your machine, touch it lightly, and it will growl and suck in air sharply. This isn't a metaphor, it makes a growling noise and the operation of the cylinders creates a vacuum to pull air into a cylinder that has ready fired, as does the exhaust exitting the chamber. Your engine breathes, it has a heart made of metal that grows hot. It has a camshaft (maybe more than one) spinning inside it and deciding the pace of each cylinder beating up and down, as steady and distinct as any human heart. An old car even has a tiny little brain, a rotor spinning around at a set time so it knows when to fire off electricity into each cylinder and keep that heart beating.
This vehicle is definitively not in any way alive, yet it is impossible to own without understanding these processes. When you sit inside one and turn the ignition (prompting the electric starter motor to draw power from the battery to make the flywheel turn the pistons in the engine cylinders while the throttle plates close which causes the cylinders to develop a vacuum when the pistons travel downward which in turn pulls aerosolized fuel through the throttle body into the cylinder until sufficient air fuel mixture pressure and the sparkplugs ignite the fuel and allow the engine to move itself without aid from an electric motor) you are aware of what is happening, while the entire vehicle shakes around you and makes a sound that screams into the primal part of your mind that you are prey. But now you're connected to this animus through iron, bakelight, and heat. When you push the gas pedal, you can feel every shift of fuel and fuel pump and throttle and air and combustion and exhaust squeezing in tandem, as fragile and powerful as your own flesh and blood.
It is something unlike the cool, easy division between mechanical device and pilot so omnipresent in the mech genre. Nor is it anything approaching the intellectualized mind-machine bond equally romanticized. Inhabiting a machine is not something that is a connection or a switch or compartmentalized or agonized. There's no metaphysical transcendence, there's no neatness or sharpness to it.
My experience, the time I had with that kind of machine, was messy. It's physical, sweaty, and uncomfortable to be swallowed up like that. But I came out of it all with a different understanding, so when I want to express some idea of a mech pilot relationship, it has to be alive in the same way as the ancient beast of iron and fire I once knew.
