Front disks - Chesil Speedster

hi there
I am about to fit new front disks to my Chesil new build. In the VW books the front disks all seem to have a backplate and yet I dont appear to have this, does that mean its missing or I dont need it?

Thanks

I noticed in US the "dust shields" are now offered as a $20 each add on to most disc kits. Guess to lower price of the kit. The shields keep water and dirt off the rotors so OEM they were on road cars driven daily. So if you don't drive in rain, puddles or dirt roads, they are not necessary. You won't see them on race cars. If your spindles are drilled for the backing plates (some are not drilled) and the plates are available - I'd add them. Noticed on new cars they often have directional vents to shoot air at the rotors for added cooling.

http://store03.prostores.com/servlet/aircoolin/the-391/VW-Bug-Beetle-Disc/Detail

My drop spindles were not drilled for the backing plates. I drilled and tapped them so I could use the backing plates.

Thanks for advice
Tim