how old can a child sit in a car without a booster seat
No. When a child reaches age 8 (regardless of weight) OR reaches 80 pounds (regardless of age), a properly fitted seat belt may be used instead of a child restraint/booster to restrain the child. However, keep in mind that the seatbelt may not fit properly even if the child is 8 years old or weighs 80 pounds. The law does require that children stay in a child restraint or booster seat until the seat belt fits properly on its own.