The law might require it, but it's not going to happen... This is a prime example of stupid laws that won't be enforced.
This is like the whole talking on the phone and driving. In Minnesota, you're not allowed to talk on the phone while driving if you are holding the phone up to your ear. You can put in a headphone, talk through your vehicle, have it on speakerphone, or if you're someone who wears a headdress, you can wedge it between your cheek and turban and that's all perfectly okay. Stupid rule, that honestly, I haven't seen enforced...