Untill 1934 all models of Hupmobiles had flat lenses. In 1934 Raymond Loewy designed the first aerodynamic,the model J which had convex lenses. I have a 1936 model N Aerodynamic and the headlights are as good as my Dodge van. I wll post the lense # when I find the manual that they are in. Call it a senior moment, I know I have them Chuck