>Why can't we equate the software inside a computer inside a vehicle with the mechanical equivalent? What then would our rights be?

There really isn't a mechanical world equivalent to the DMCA anti-circumvention law or the derivative works restriction of copyright.

I think the DMCA anti-circumvention laws should just be repealed since it doesn't appear to be effective.

And I think there is a good argument that modifying software you license already is fair use.