Asker, you are quite correct in your assumption that Conti 3s have varying rim protectors.
The ones I had on my mk5 GTI (and briefly on my mk6 too on my old 18'' BBSs) had mahoosive rim protectors.
If you look at this picture and your eyes are good enough or you've got a biggish screen to view them you can see the difference between the flush sitting Conti 2s on the rear and the tractor tyre like Conti 3s on the front axle.
The ones I've just fitted to my 19'' BBSs have much smaller rim protectors, and I mean MUCH smaller.