What you smell is likely VOCs (volatile organic compounds). These are the chemicals responsible for that new car smell. I can't say for sure but if there are any paints, adhesives, plastics etc. VOCs coming off these could be the cause of the smell. It's also possible the smell is coming from a fabric treatment such as an antimicrobial or stain repellant. It should eventually go away or at least be greatly reduced. I'd wash and dry them according to the instructions and hang them up some where that gets good air flow.