dude, there was a mod uploaded like a couple weeks ago that adds the rear axle and driveshaft from the grand marshal. just look.
Sorry i searched for "legrand rwd" on google and i found only 2 mods. but thx for the link. it's a AWD only mod...
okay my bad i just realised i have another mod that adds the rwd transfer case but has no mesh so you need both mods together. get this https://www.beamng.com/resources/cjd-special-tunes.1583/