Specific component material composition

I'm looking for information regarding the specific composition of some of the materials used in construction of an XJ, including the coil springs, control arms, leaf springs, body panels, and interior trim.

Does anyone know where to find this information?

I know the springs are made of spring steel, the body panels of carbon steel, etc.. but I am looking for specific information.

Someone has to ask why?

It may also depend on the model run.

Not sure what you are looking for but an XJ is pretty much the same as any other car, except for a little extra cast iron and steel for the transfer case & front axle. And if your lucky and been out to play lately, some extra mud.

http://www.wasteonline.org.uk/resources/InformationSheets/vehicle.htm