The ornamental design for an extended truckcabpanel, as shown and described.
FIG. 1 is a perspective view of the rear and left side of an extended truck cab panel.
FIG. 2 is a rear view thereof.
FIG. 3 is a front, inside view thereof.
FIG. 4 is a left side view thereof, the right side being a mirror image of the left side.
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The broken lines shown in the drawings depict portions of the extended truck cab panel that form no part of the claimed design. The partial truck body shown in broken lines is for the purpose of illustrating environmental structure, which forms no part of the claimed design.