What articles did you find, exactly? What primary evidence are they basing their claims on? Many of the numbers you'll find with a google search are unclear about what they're comparing to - I believe both of the fatality numbers above (71% and 54%) are relative to completely unrestrained kids, which is not the relevant comparison.
The 45% number I specifically discuss in the other comment, but every independently reproducible study using publicly available data has found much smaller effects, around 10-25% for minor injuries and no statistically significant difference in severe injuries.
To be clear, I'm not saying "don't use car seats," I'm saying that the evidence doesn't support mandating them through age 8 (or 12!).
Our kids would be much safer if we drove everywhere at 15mph - less convenient, but it would prevent many unnecessary deaths. Unfortunately, it is impossible to do anything in the world without risk. So we're forced to balance convenience against safety every day, whether we want to admit it to ourselves or not.