Can Anyone Recommend a Gag, Muffler or Muzzle for My Baby?

Last week we gave you a survey asking about the most annoying sounds of all time. The indisputable winner was "crying children." Oh man, if I can't relate. My two-month-old baby cries every time he's in the car seat. When we drove to Seattle he cried for three and a half hours. When we stop at a stop light, he stops crying because he thinks we're done and he's getting out. But as soon as we accelerate, he starts crying again. The faster we go, the harder he cries.

With babies, there's not a lot you can do. Sometimes they just cry.

I'm thinking someone should invent something to cover my baby's mouth in the car. I'm looking for a muzzle or a jaw strap -- like a "cry dampener." Maybe a binkie strap. I just need some kind of baby gag.

Online I found a Baby Shusher but I don't think that'll work.

I'm thinking more of something like this: