I claim the ornamental design for a seat belt cover with lettering, as shown and described.
FIG. 1 shows a seat belt cover with lettering;
FIG. 2 is a perspective view of the design;
FIG. 3 is a front elevational view of the design, in an un-rolled state;
FIG. 4 is a rear elevational view of the design, in an unrolled state;
FIG. 5 is a left-side elevational view of the design, in an unrolled state, the right-side elevational view being a mirror image thereof;
FIG. 6 is a top plan view of the design; and,
FIG. 7 is a bottom plan view of the design.
Areas shown in a dot-dot-dash broken line are environmental and form no part of the claimed design. The evenly spaced dashed lines in several figures represent stitching. The oval shaped fuzzy patches seen in FIGS. 2 and 3 are representative of the texture of the entire surface and is continuous throughout.