Earlier quoted context omitted.
The regulatory differences are also huge. Apple has negliglible experience dealing with the raft of certifications and demonstrations of compliance that car manufacturers have to go through.
They have been working in a similar highly regulated space (medical devices) for years.
> The ECG app is intended for over-the-counter (OTC)use. The ECG data displayed by the ECG app is intended for informational use only. The user is not intended to interpret or take clinical action based on the device output without consultation of a qualified healthcare professional. The ECG waveform is meant to supplement rhythm classification for the purposes of discriminating AFib from normal sinus rhythm and not intended to replace traditional methods of diagnosis or treatment.
https://www.accessdata.fda.gov/cdrh_docs/pdf18/DEN180044.pdf