Do the carpet in 4 pieces. 1st piece covers the tunnel. 2nd and 3rd pieces cover the footwells on either side of the tunnel up the firewall. 4th piece covers the area under the seat to the back wall of the cab. You may need more or less pieces, it's hard to tell just looking at a picture. You can bind the edges next to the tunnel or just butt the carpet up to the tunnel, whatever look you're going for.
No one lives forever, the trick is creating something that will.