Apparently the auto manufacturers are not pleased with people tinkering with their products and want to enforce sections of the "Digital Copyright Act" that the lobbying group that represents them. They feel that the laws apply to automotive technology and are arguing that enthusiasts can do everything from render vital systems inoperable to roll-back digital odometers. Basically the same things we've been able to do, but haven't, for decades.
http://www.autoblog.com/2015/04/20/a...s-car-repairs/