Not 100% sure of this but I am pretty sure you can buy Stock Interior mass backing carpet (made by ACC) very close to the ECS brand for about half the price.

Only reson I found this out is when I called ECS they told me they would nit be taking any orders for carpet any longer.
So I called ACC.

Now they do not ship it flat, but becuase it is MASS BACKING, it will lay flat to form after about 6-8 hours.

I think the key is MASS BACKING - it replicates the underside of factory carpeting very well. It is not the cheap looking white plastic stuff, it actualy black and at least 1/16 of an inch or more thick.
Because of this , it falls back to form very quickly once taken out of the shipping container.

I did my Challenger with it and the carpeting is dead nuts on for fit.
I just dropped it in, trimed of excess from sides and top (toe board).
It is not flimsey and I did not even need to use ANY glue at all.

Was VERY impressed.

Now I amd not sure if it 100% perfect with regard to toe pad and heel pad, but I compared to an original E body front carpet and sure looked darn right to me - but I am no expert.
Just though I would share.

Bill