In reply to cha1n: You could look at a Buffalo sleeping bag
http://www.buffalosystems.co.uk/Sleep_System_main.htm - they are still synthetic but IIRC they have a 'pile' or fleece finish inside rather than tightly woven micrfibre. Apart from them, I can't immediately think of anyone making sleeping bags of out of anything other than pretty similar synthetic fabrics.
You can certainly get liners in a whole range of materials: cotton, silk and various weights of fleece.
Equally, if you are car camping why not take a full size airbed, cotton sheet and a single duvet?