Do I need car seats for small children?
The Guru Take
Potentially not. Check your local rules.
The law depends on your location, but it is commonly known that the car seat laws with taxis and livery services are looser than they are for personal vehicles. The topic is covered in the link below. Unfortunately, the laws are currently not clearly defined for rideshare services where the drivers (say for UberX) may not have taxi or livery licenses.
You may find these articles useful.