I'm going to call some upholstry places to get estimates. I think maybe I'll take the seat covers off myself, and just have them replace the middle pieces of fabric with something black. Maybe if I do all the removing and reupholstering, it will minimize cost. My other thought was to take them off and just dye all of the seat upholstry black. That'd be cheap and effective, but shrinkage could be a prob. I really want the two tone look though.
my mockup:
