The ornamental design for a trailerwashbrush, as shown and described.
FIG. 1 is a top-front-left perspective view of a trailer wash brush showing my new design;
FIG. 2 is a bottom-front-right perspective view thereof;
FIG. 3 is a top-rear-left perspective view thereof;
FIG. 4 is a bottom-rear-right perspective view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a rear elevated view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof;
FIG. 9 is a right-side elevational view thereof; and,
FIG. 10 is a left-side elevational view thereof.
The broken-line showing of a wheel assembly in FIGS. 1-10 and the broken-line showing of a guide wheel assembly in FIGS. 1-8 and 10 are included for the purpose of showing environmental structure and form no part of the claimed design.