Just announced, and this makes sense. Duck canvas seat covers w/ water repellent finish by Carhartt, created for Ford F150 and SuperDuty trucks. The press release says you can get them here, but searching does not find them...
A friend of ours had seat covers made from old military duffle bags, for his Jeep as below. Might even be better than the Carhartt jobs... the handle in back is key.
