Also, modern cars with their proverbial weld-shut hoods have killed my inner mechanical engineer.
I would pay a healthy premium for a solid off-road-capable vehicle that wasn't intentionally as locked down as possible. I imagine one of the chief challenges is manufacturer fear of NHTSA or EPA retribution when someone releases an ECU image that turns a Prius into a rolling coal in exchange for a bit more power. I doubt this is going to change without explicit regulation protecting tinkering.