Saw this from RCShopping.com
http://www.rcshopping.com/profra.jsp...2136&proclass=
http://www.kfactoryracing.com/produc...2136&pageNum=1
Its only description is that it is a carbon radio plate for the E4. However, looking a little closer, it looks like the aluminum piece in the middle of the picture is for the hinge mechanism for the battery door on the E4JS.
I tried looking at the KFactory site for more information but there is nothing there. Can anyone confirm that this is an upgrade for the E4JS?
edit: Just found my answer through Google.
http://www.rcracingshop.com/shop/pro...c4d102e1be40ce