In one of our 3 cars, dd, at 4'4" and about 60 lbs. DOES fit without a booster. Not only does she meet the 5 criteria points to be without a booster, with a booster, she sits too high and the belt comes across her upper arm instead of between her shoulder and neck as it should.
So, it depends on the child and on the car. I am absolutely the biggest safety freak, so I would never do anything that I felt was not 100% in dd's safest interests. In her case, using a booster *in this one vehicle* was not as safe as using none. In the other two cars she uses a backed booster in one and backless booster in the other because they fit the best for her in those vehicles. I use what keeps her the safest in each vehicle. I, too, was worried about the whole 4'9" and 80lbs. but the fact of the matter is that it's a guideline and a good one at that... but it's not a hard and fast rule. If the child is safer without a booster, then having a booster is not only not helping... it's dangerous.
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