As per an Auto Car article - expect a recall soon:
Thousands of Smart #1 EVs could be recalled due to a fault whereby the rear passenger’s seatbelt may unbuckle during a high-speed manoeuvre.
Discovered by Finnish automotive magazine Tekniikan Maailma (TM), the fault occurs when three passengers are seated in the rear of the car. When a high-speed evasion movement is made, the central passenger’s belt lock pushes down on a side passenger’s lock, unlocking it.
This fault occurred during multiple high-speed swerve tests on a #1. The next day, it was repeated with another #1 at a different location, and the problem occured again. All cars were travelling at around 45mph.
Smart has confirmed to TM that it's investigating the issue.
Smart told TM: "We take this matter with our principal very seriously. Our principal has already started his own investigations, and we will tell you about them and the measures as soon as possible.”
https://www.autocar.co.uk/car-news/cons ... ault-found