Euro NCAP has released details for its first ever rear impact tests where only five of the 25 car seats tested scored "good" for whiplash protection.
The whiplash tests were carried out on the front seats of 25 passenger cars throughout 2008.
The five cars to receive a "good", or green result, were Volvo's XC60, the Alfa Romeo MiTo, VW Golf VI, Audi A4 and recently crowned European Car of the Year winner Opel Insignia.
And while the safety agency noted the development strategies employed by manufacturers to prevent whiplash, it said it was concerned by the low number of seats receiving a good result.
Five stars, but...
Eight of the 25 seats tested received a "poor" rating, indicating that the seat's occupant would have a higher risk of developing long-term injury following a rear end collision.
These cars were the Daihatsu Cuore, Citroen Berlingo, Hyundai i10, Citroen C5, Ford Kuga, Daihatsu Terios, Peugeot 308CC and the Suzuki Splash.
Of these eight cars, three of the vehicles - the Citroen C5, Ford Kuga and Peugeot 308CC - were awarded with five-star ratings in adult occupant protection during 2008.
Active head restraints no guarantee
"Marginal" (or orange) results for the more expensive BMW X3 and Mercedes-Benz M-Class's active head restraints (that move forward to "meet" the head in a collision) also proved that added features did not necessarily increase the performance of the seat.
From 2009, whiplash testing will form part of the Euro NCAP's new assessment programme for adult occupant protection. The first results for vehicles tested under the new rating system will be released in February 2009.