You may have the type of windshield rubber that needs an external stainless steel trim piece that was never installed.
or
It could be a windshield rubber that needs an insert rubber band to help push apart that big seal and close the gap, sealing against the frame and glass.

Jim & Caroline
The highway is for gamblers, better use your good sense."
Gooday-that's my 1¢ answer due to the lousy economy ~ cause I ain't got - no . mo . doe
Every Shaver | Now Can Snore | Six More Minutes | Than Before ... | Half A Pound for Half a Dollar | Spread On Thin | Above the Collar || BURMA-SHAVE