I found that all the mats smelled to me, but I did a sniff test when I got them. I think they all give off a smell and how smelly they are when you get them depends on how long they have aged.
I didn't notice the smell in the store, it seemed the least smelly, but when I got home and put it in the confined space of my sewing area I did notice it. So I just put it in the garage for a while, and on a sunny day I put it on my deck, a good flat surgace. It did take a few weeks before it was totally gone, but no problem now.

I once left my Fiskars mat in the back seat of the car not thinking that when it got hot from the sun that it would droop over the seat but it did. I did everything that I was told to try to straighten it up but it would not flatten. I finally called the Fiskars company and after telling them the many things that I had tried to flatten it back out, they told me they would send me a new one at no charge. They did and I'm still using it 4 years later. Maybe you could try that if one of them was a Fiskars.

I have a similar story. I went to the grocery store, got home, and DH unloaded the car for me. After I had put everything away, I told him I knew I had bought a couple chickens. He went back out and looked again, then decided I must have left them in the grocery cart. (I have a tendency to do that if the sacker places anything on the bottom of the cart.) A few days later, I started smelling something. Searched the car from top to bottom, and found the chickens in the far back corner of the trunk. Luckily, they hadn't been smelling long enough to ruin the car.