You're driving through rush-hour traffic when you hear the ominous un-click of your preschooler's seat belt, usually followed by a smug little giggle, or the classic, "I just need to get my something on the floor!" You keep one arm on the wheel while frantically, but futilely, trying to grab your unbuckled angel and loudly insisting she put her seat belt back on, "Right now!" Most 18-month-olds would unbuckle themselves in a heartbeat if they had the dexterity to do so. Which is why unbuckling is so tempting when your little one hits 40 pounds and trades the confinement of a 12-point-restraint car seat for the freedom of a booster seat and seat belt.
Explain to you little one, before even turning the key in the ignition, that everyone must always wear a seat belt when the car is turned on. Add that even if the car is stopped at a traffic light and not moving, she must never unbuckle her seat belt. Refuse to start the car until she, and your other children, are securely buckled. Laying the expectations beforehand probably won't deter a child who's intent on defiantly unbuckling, but it will clarify the issue if she's unbuckling impulsively to retrieve a fallen toy from the car floor.
Reward her at each stoplight she remains in her seat belt with a small sticker. Give her a small sticker book at the beginning of each ride and give her stickers from the glove compartment as you drive. Explain that you will confiscate the sticker book until the next ride if she unbuckles her seat belt at any point. Along these same lines, remember that an occupied child is less likely to make multiple escape attempts between the grocery store and home.
Pull the car over immediately if she unbuckles her seat belt. If she unbuckled herself because she wanted to adjust the shoulder strap digging into her neck, fix the twisted seat belt or raise her booster seat and re-buckle her seat belt. Reiterate again that she must never, ever unbuckle her seat belt. If, however, she unbuckled herself simply to spite you or to test your reaction, you need to implement a mobile timeout.
Restate that she must always keep her seat belt on and if she doesn't then you will have to stop the car for a timeout every time she unbuckles herself. Check your email or clean out your glove compartment for the next few minutes and completely ignore her wails and protests. Afterward, explain that before you can start the car, she must agree to keep her seat belt fastened.
Conduct an outside timeout someplace safe, but nearby for an exceptionally strong-willed child who remains undeterred by timeout inside the car. For example, place your child in a three-minute timeout under a tree in a corporate park or on a bench outside a strip mall. Explain again that she may not unbuckle herself, ever. Stand 10 feet away from her and fixate on your phone while she does her time, and, most likely, wails like she's on fire. She'll live. Being forcibly removed from the car and made to sit in a strange place, even with you 10 feet away, is an effective deterrent for even the most persistent children.