It is a legitimate concern. There is all sorts of related stuff going on in the periphery, and has been for years. FasTrak (toll pass) records have been used by

It is a legitimate concern. There is all sorts of related stuff going on in the periphery, and has been for years. FasTrak (toll pass) records have been used by divorce attorneys and whatnot for the past decade or so. Many Bay Area cities operate license plate cameras to monitor all comers and goers. I would not be surprised if other agencies started utilizing this information. More and more we will see OnStar-like integrated systems come standard (featuring remote start/stop). "Black boxes" (event loggers) are already becoming mandatory in new cars. Much of this diagnostic data can be offloaded wirelessly. Have you seen the demos of Jeep, Ford, Toyota, or Chrysler vehicles being "hacked"? The attackers were able to access the CANBUS (or whatever the particular ODBII spec in use) over the internet. This is absolutely a concern for mass surveillance. If you want to get really paranoid, think about what could happen during disasters or protests. You may see your car cease to operate altogether. But just to respond to the original question... As you mentioned this device requires physical access so it is not particularly alarming. Definitely a concern for future iterations though. Presumably those would not be publicized.