What are some safety precautions I should take for my 18-24 month old child when traveling by car?

In car seat strapped. If your wife can travel along side the child its always more reassuring for them, and she can address any need he or she might have while in the car.
Couple suggestions. Your preferred plan is for baby to face the back window in a convertible seat.The neck is still vulnerable to permanent damage if forward facing. It is acceptable to forward face after two years old if over 20 pounds but it is preferred to rear face to the seats rf weight limit. Never leave a child alone in a car while you run an errand. You could lose your child to a thief or heatstroke.