I think you are writing about Event Data Recorders.
Unlike Flight Deck Recorders, that keep track of at least 88 parameters and retain the most recent 30 minutes of pilots' conversation, the primary purpose of an EDR is to assess automotive safety hardware; specifically, to gauge the efficacy of airbags and their deployment strategies. Succinctly, if an airbag doesn't go off, the EDR has nothing to report.
If an airbag deploys, though, a typical EDR may record pre-crash vehicle speed, driver inputs of accelerator or brake, the nature of the crash, seatbelt use/airbag action and any automatic post-crash activity such as collision notification.
By contrast, an automotive EDR stores vehicle and occupant information in that brief period (seconds, not minutes) before, during and after airbag deployment. Like a 15-second data spool being continuously monitored and—only in the event of a serious crash—being captured in memory, typically part of airbag-management electronics.
Does your car have an EDR? Check the owner's manual. Even those without EDRs will typically have a statement noting this.
Based on the information I found during the few minutes I spent searching this on an obscure web portal called, "Google", I believe that "The Nissan LEAF is equipped with several data recorders:
-A data recorder for diagnosing repairs
-An Event Data Recorder (EDR) that records data in crash or near crash situations, such as an air bag deployment or hitting a road obstacle. The EDR records data related to vehicle dynamics and safety systems for a short period of time, typically 30 seconds or less.
-Telematics and recorded vehicle data for features, analysis, and research.
The Nissan LEAF records data concerning various vehicle systems, location, driving performance, and operating conditions. Some of this data is transmitted to Nissan through the vehicle onboard telematics system. Without your consent, the vehicle will de-activate the vehicle telematics system in your vehicle, and certain features, including all telematics, of your vehicle will not operate as intended."
I hope you find this information useful.