The ornamental design for a frameless curved windshield, as shown and described.
FIG. 1 is a perspective view of the frameless curved windshield, in accordance with the present design, from a point above, to the right, and in front of the frameless curved windshield.
FIG. 2 is a perspective view of the frameless curved windshield, in accordance with the present design, from a point above, to the left, and behind the frameless curved windshield; and,
FIG. 3 is a perspective view of the frameless curved windshield, in accordance with the present design, from a point above and in front of the frameless curved windshield.