People here have used 2' foam tiles for floor covering and for insulation. Usually the tiles are a mix of bright colors or industrial gray.
I found some at Menard's today that had a woodgrain look on one side and a light
tan on the other.
And they were on sale. A four-pack had been $17.99 but they were on sale for $8.99 a four-pack.
I bought 4 of them, to try out on the floor and on the bench seats in my Compact Jr.
Not sure how long the sale runs or if all stores have them.