We got a great bag for our carseat from Babies R Us. It has wheels on the bottom and straps to use it as a backpack, as well. I think it was under $30. After seeing the damage to both that bag and the one we use for our stroller, I would never send a car seat through without some sort of protection. Those bags come out filthy! Also, don't depend on the airline having plastic bags. I've been behind several people in line who asked for them only to be told that they were out, or don't use them anymore. If you want to be sure, bring your own bag! I checked our infant seat through 5 years ago without a bag and it came out missing a piece to the base and we had to purchase a new base - the airline said they don't cover damage to baby stuff anymore. Gate checking can minimize some damage, but our gate-checked stuff still comes out really dirty and sometimes wet if there is precipitation when they are loading.