Dunno the exact ruling for Wisconsin, but you can add your lights/reflector strips on the lower rear wheel spat extensions. It gives them another utility function. It is comparable to the locations of mud flap reflectors on trailers. I got the idea this AM following a 2011 VW Golf. It had red rear reflectors way below the rear bumper but it was placed all the way to the corners. Could an idea like this work for your state.
You could use the renderings and sketch out your rear markers ideas.
