I just read a couple of articles outlining a desire by the Automakers Alliance to have our vehicles fall under the restrictions of the Digital Millennium Copyright Act. That is, the automakers wish to make it illegal for us to work on/repair/modify our own cars...with emphasis on the ECU code. While this thought is not a law, it has been presented to the 2015 US Copyright Rulemaking proceeding.
Effectively, if allowed to pass as law, the vehicle we purchase will come a with a EULA for the software (directly, or inferred), and any actions that may effect the software as an input to it (think: changing tire size) will be restricted by DMCA.
I refrain from posting urls/links due to not finding specific language granting me permission to link to any of the URLs I found the info at. However, this is an effective search string with most browsers: DMCA automobile 2015