When I bought my '68 Cougar, there was a brand new passenger door mirror lying loose in the trunk, it looked exactly like the drivers door mirror, but when you tried to attach it, it just cleared the glass by a whisker as it was a mirror for the Mustang of the same year. The stem is more upright for the Mustang, where the Cougar, needs the stem to have more of an angle, leaning away from the glass. Bought and installed the correct mirror and sold the Mustang one on the net, for NZ$65.