The foam back carpet was a terrible idea, left over relic from the seventies, it was used as "kitchen carpet" in the US, I'm surprised Cobra was and I guess still using it. They are most likely not even available in the US any longer.
The easiest way to replace this crap is with regular commercial grade "tufted" carpets, readily available at your neighborhood flooring stores . Than once again the problem is the weight with these goods which makes it harder to install once all the previous crap has been removed as I think JJ described it well previously.
The best results can be obtained from automobile carpets (without the foam back) , these are light weight and go around compound curves much more easily. They can be purchased at the neighborhood auto upholstery shops. Even if more expensive remember you don't need a large quantity, so it won't brake the bank.
And since on this subject, please use a good quality contact cement BUT NOT THE GREEN KIND as you may end up with the carpet as headwear- they just don't hold. Unfortunately the old fashioned contact cements are only available in small cans any longer which makes them more expensive.
I could be wrong here as I only tried the local hardware stores and not online.