Some consumer people have been doing lab testing of car seats again - I know the AA were involved, not sure who else. I find it shocking how much some seats differ in their safety. There were about 50-60 tested. This is the link if you ant to see how your seats did:
195.167.162.28/aamotoringtrust/pdf/childrestraint_testresults.pdf
Can't remember how to do proper link so you coud jsut copy and paste it into your address abr - sorry!