How do you install the long walls ?

How do you make the driver side covered walls that are longer than 8 feet ? Is it all one special piece, is it 2 pieces, and how do you pad it with let's say indoor outdoor carpet it and then attach it to the wall ? Is the fabric just to the edges or is it wrapped around to the back around all edges ? how is this this stuff done ?
Thanks

if your going to carpet it, i'd cover the wall with 2 pieces of your backerboard, them glue and a few staples. them make a moulding strip, where the carpet meets headliner.that could be done with carpet wrapped, around and stapled on backside