Good advice there. I think one other thing that's really important is to buy  a new one when your child outgrows it!

I don't know how many times I've seen toddlers being squished into car seats that are obviously far too small for them to the point where the straps will barely buckle. That's a clue: if the straps no longer fit comfortably and both mum and child are red faced by the end of wrestling them into it, the baby's too big for it. There's a reason why they sell them with age and weight guidance.

And just as an added note of interest for our Australian mums, the law there says every child restraint sold in Australia must carry the red and white Australian Standard AS/NZ1754 sticker. Be careful if you order one online from another country because apparently the majority of child restraints from overseas don't match these standards, even from the States or Britain. You can't use them legally. If in doubt, ask the manufacturer if they're compliant with that standard (rather than the store who'd probably say yes anyway to get the sale. I have a suspicious mind.)