I’d recommend you buy a bag instead. Way more durable, easy to use, and you don’t have to worry about finding the plastic bags at check-in.

Here’s what we used. I’d highly recommend it ... worked great.

Airport Gate Check Bag - Car Seats - Oyaco - Babies"R"Us

(Ignore the “gate check” logo on the front. We always used it at check-in/luggage drop.)