Booster seats for kids?

[lime1]

Having sussed out the issues with boot space I now need to plan for the back seats for my upcoming trip to the US. I have 2 boys aged 6 and 8. Will I need booster seats for them or will the back seats be okay without? They have backpacks which double as booster seats so I could take these if needed but easier to travel lighter if they're not required. Thanks

[LuS1fer]

I don't know the US law but I imagine they wpould be fine without as they are quite sculpted and bolstered. Won't be able to see much though.

[Rogue86]

I think its state-dependent so Id check first, a quick google came up with ghsa.org which lists requirements for each State and potential fines.