MIL put dd's life in danger, she thinks it's funny

[sarsums]

Hi, I'd really appreciate some opinions on this. Am I over reacting??

My MIL looks after my 1 year old daughter every Thursday. Today she and grandad took her out in their van (he's a builder) without a car seat. MIL held her in the front seat. She knew that I wouldn't be happy with this as she 'let it slip' to me that they did this, and had a joke with dd that they "weren't going to tell mummy".
At the time I was cross in my head, but I'm a total wimp and didn't say anything. Now I'm upset and fuming.
I think it shows complete lack of respect for me, and a lack of responsibility with my daughter's life. What would you do?

afaik rear facng is safest and read once on mn that some scandinavian countries nsist on rear facng seats for toddlers as well as babies

Back in dec i had this issue with my sister, who took DS in a cab to see my mum,who lives nearby. she was planning on walking, but it was raining, so she took him in the cab,sitting on her knee
she thought it was ok, but obviously i didn't, and i called her a couple of days later to ask her, in future, to use a car seat
she did get uppity, as she's got 5 of her own, is a former childminder (registered) and now runs a day group/play/afterschool thingie.
her objections to my objections were "it was only a short journey", "what about buses and trains?" (physics are diferent, you don't get shunted as much in a bigger vehicle).
We had a bit of a row,and (she's 15 years older than me) i think it boiled down to "mine were always alright, accidents hardly ever happen" etc etc, but i expalined that the roads are mental these days, law says so (although the law in cabs is a grey area)etc etc , and she's had to come round.
i think her professionalism kicked in, as she said that as he was my son, she'd have to abide by my rules.
however, in the case of your MIL, i think the jaw-dropping "together in heaven" (does she wanna get there first?) comment isn't so much her being irrational, as just showing you that she doesn't take you seriously at all. it came across to me as being flippant and calculated to belittle your concerns.
you are in control of this situation, and whether your ILs get to see you DD again is up to you, don'tforget that. your terms, your say.
good luck.

oh yeah, and, having been brought upin rural wales, a treat in my childhood was to ride in the back of an estate car, behind the grille, with or without the dogs!
can you imagine that, now?