As a comment for future SE owners, the smell from the trimmable rubber mat from Amazon on the front page never dissipated after airing it out for 2 months (left it outside, flipped it every week to make sure both sides are exposed to the air). I even washed it with soap and a brush.
If you're sensitive to the smell of rubber/plastic, do not get this mat. I think there may be some genetics at play ~ my SO can only smell the rubber/plastic if it is strong (there are many items I am offended by, but my SO does not notice). My SO does not mind the smell of the mat, but it's still very offensive to me.
I wish that 3D Mats made someone for the back ~ their front mats have been perfect.