The ornamental design for a seatbeltshield with single attaching strap, as shown and described.
FIG. 1 is a perspective view of the top and front of a seat belt shield with an open single attaching strap showing our new design.
FIG. 2 is a perspective view of the rear and bottom of the seat belt shield with the open attaching strap; and,
FIG. 3 is a perspective view of the seat belt shield with attaching strap closed and a reference only person wearing a seat belt drawn in phantom.
It being understood that the broken lines of the seat belt strap in FIGS. 2 and 3 and the environmental matter in FIG. 3 are for illustrative purposes only and form no part of the claimed design.