I think the toy cars are 100% out of line for Mass.
Does anyone remember children having those little Bible story picture books to look at during Mass? Do they make them anymore?
Exactly. I may be wrong, but the parents I see now seem to really want their children to behave - but have no clear plan to cause it to happen.

Thus my idea of publishing suggestions for young children at mass - the same as I see in our bulletin for keeping marriages strong, etc. I immediately see the danger of letting a toy car into mass, for example, and never let mine do so. However, I was also taught to think this way by my own parents.
I believe parents in my parish see other parents giving kids snacks, noisy toys, etc. and they just figure this is the way you do it and hope for the best. Glaring at them isn’t the answer - helping them figure out a better way is.
Even when they were very tiny, I always put a “shhhh” finger over my infants lips and did a quick “no” shake of my head when they start to babble during mass. Did they have a clue? Absolutely not. But I believe it contributed over time to them learning not to speak during church - both by the “negative” finger and facial expression, the positive ones I gave them while they were quiet, and the example I set of my own behavior (phsyical gestures of support and correction but not verbal ones). Now granted - this means that for the majority of 2 to 4 straight years, I was more focused on my child than on the liturgy - but, for me, that was part of caring for these precious gifts I was given by God. Periodically, I did leave them at home so I could get in a full mass of actual worship, but this was not my norm.
Now I get the pleasure of being able to attend Mass, my children (7 to 15) present, and usually I will not once have to even have a thought to their behavior. No trips to the bathroom, no whispers, proper body positions, verbal participation in the mass
sigh For me it was well worth the years of constant vigilance and correction. But like I said, I was taught to parent, and I have a definite impression that many parents want this kind of outcome but have no understanding of what to do beyond attempt to distract their child, take them out when noisy, and get fed up because they feel it will never end.
Sorry…kind of ranted on it, but parenting is sort of my thing

(And I admit, writing is not - your kind tolerance is appreciated for my misspeaks and my errors.)
God bless!