Well, a rear seat is a lot of money. $400 and more. I had some scrap seat pads,steel and made my own. Works well and can be removed. Sorry it is dark.
Click image for larger version. 

Name:	2011-12-27-12-54-49.jpg 
Views:	408 
Size:	134.5 KB 
ID:	4393Click image for larger version. 

Name:	2011-12-27-12-55-19.jpg 
Views:	397 
Size:	142.0 KB 
ID:	4392Click image for larger version. 

Name:	2011-12-27-12-55-58.jpg 
Views:	389 
Size:	134.1 KB 
ID:	4391