I've been searching the NHTSA website and came across this interesting March 12, 2012 submission from Tesla in the form of a 5-page comment letter in response to proposed NHTSA rulemaking regarding Theft and Rollaway Prevention:
http://www.regulations.gov/#!documentDetail;D=NHTSA-2011-0174-0029
It describes operation of the Model S keyless system in detail for vehicle entry, starting and shutdown.
http://www.regulations.gov/#!documentDetail;D=NHTSA-2011-0174-0029
It describes operation of the Model S keyless system in detail for vehicle entry, starting and shutdown.