havin owned both, and done a coupe to sedan exhaust swap, i can say it is the same, HOWEVER length is different. coupe exhaust are slightly longer so u might find fitting a coupe exhaust might have the tip sitting quite flush with the bumper "line"
my new 4 dr shiter has a gtr exhaust, it sits quite low, and one mount needed to be changed and it needed to be extended about 20cm (the piping).
so all in all ANY r32 exhaust will fit a sedan, just might need some slight modifications, nothing major.
oh s13 exhaust will fit as well