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.

TM has labelled the issue as a “dangerous design flaw”, warning: ”Until the fault is fixed, it is not safe to carry three passengers in the back seat of the Smart.”

TM added that the #1's back seat with the current belt arrangement “is not suitable for three passengers” and questioned how Smart had not discovered the fault itself.

One explanation was the use of crash test dummies, rather than humans in a real-life scenario.

The issue, as illustrated by Tekniikan Maailma

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.”

In a statement supplied to Autocar, Smart said: "Smart is aware of the questions raised by Tekniikan Maailma during their testing, and is treating them with the utmost urgency. Ensuring the safety of our customers and all road users is our number one priority, with our models having been awarded a five-star Euro NCAP rating, passing some of the world's most demanding safety tests in the process. Our internal R&D experts are now conducting a comprehensive investigation of the matter."

A recall seems to be the most likely outcome.

TM confirmed that the problem doesn't affect the Volvo EX30, which is based on the same Geely SEA platform, nor the larger Smart #3.

A near-identical issue, affecting the Seat Arona, Seat Ibiza and Volkswagen Polo, was uncovered by the same publication in 2018. 

Once the problem was identified, the Volkswagen Group redesigned the belt lock fixture and advised customers not to use the middle seat of affected cars until the fix was applied.