The Swedish authorities Folksam in coorperation with the British Thacham have tested modern carseats protection against whiplash damages.
Great results for the Civic. Just below Volvo V50, S80 2007 and Saab 9-3
Text in Swedish. Points are on page two.
http://www.vv.se/filer/41777/whiplash_december_2006.pdf