[knorker]

Just like every other car manufacturer?

My understanding is that you choose which car to buy, and then you pay them thousands to flip a bit to enable extra horse power, on the same hardware.

Or you get some shady garage to chip it for you.

[dismal2]

this isn't true. you can barely get any additional power out of naturally aspirated engine with software tuning, and sure you can do this for a short while on turbo engines but good luck running it reliably without spending money on various other modifications like cooling, engine internals, etc. manufacturers tune for a combination of gas milage, longevity, and to meet emissions regulations.