Independent European NCAP crash-testing has revealed potential safety flaws in the Mazda2 supermini and Volvo V70 family wagon.
During the tests, problems were noted with the deployment of airbags in both cars.
In the frontal impact test of the Mazda2, a small disturbance shortly before impact led to
a delay in the firing of the airbags and protection of the front seat occupants was compromised.
Although these disturbances are not part of Euro NCAP's tests, they could occur in real l accidents.
In the case of the Volvo V70, curtain airbag deployment was delayed in the side pole test.
Both manufacturers have taken steps to rectify the problems in their vehicles. Mazda has improved the airbag control software in production cars, and Volvo has also agreed to modify production cars.
As a result of the commitment shown to modify the cars to the upgraded specification, Volvo and Mazda were granted retests.
During the retesting, the airbags of the Mazda2 deployed as expected, but the Volvo V70's curtain airbag again fired late. Volvo is now investigating this issue.
Michiel van Ratingen, secretary general of Euro NCAP, said: "This is exactly why Euro NCAP exists - to independently evaluate the protection that these cars offer consumers and to spot just this kind of error.
"If there is a safety problem, we will not re-test the vehicle unless the problem is fixed on all cars."
Of the results released in the latest round of testing, four cars received five stars in adult occupant protection. These were the Mazda 2, the Mercedes-Benz C-class, the Renault Laguna and the Volvo V70.
The Renault Laguna would have been Euro NCAP's highest-ever scorer in adult occupant protection if it had not lost a point for the opening of a rear door in the side impact test.
None of the vehicles achieved higher than three stars for pedestrian protection.
