Were Y straps ever worn with panzer wraps? All pics I can find show them being worn only with a belt.
I've looked in a book we have and theres certainly one person in the picture with some straps on, whether they are Y is hard to tell 
but later on in the same book there is a mention of them wearing them (canvas "Y" straps) in North Afrika
I can attempt to scan the piccie (not sure how it will turn out) alternatively if you have a copy of German Army Uniforms and Insignia 1933-1945 by Brian L Davies the picture is on page 92, picture of the 116th Panzer Division. (209 for mention of the canvas Africa ones)
Edited to add that it isn't the black wrap, I can only find those shown with a belt ...
both my black 'Panzer' and field grey wraps have holes in the back so the belt is worn around the front but inside the wrap at the back, I think this was another idea to prevent snagging while afv crew were in confined spaces.
