car seat suggestions

[sscargo]

I need to "duplicate" this seat. I have little experience with this type of fabrication and need suggestions. I plan on creating as much of the structure as reasonable so an upholstery expert can carry on.



this is the  basic concept I have for the structure. I'm thinking to build the connect the two backs into a "W" shape.  leaving the bottom 2-3" to mount, and then slide in 2 "bottoms" the backs are currently planned to be layers of masonite .



any and all thoughts are appreciated.  I was wondering if I should use masonite, or sheet PVC? any mounting ideas?

I'm also considering cutting out the center of the bottom and covering with webbing ?

also any suggestions on a good material? It will be a dark red and in the sun I'm worried about fading. it will also need to be durable as it will be stepped on to get to the back seat.


Thanks
Mat