I had a friend order a Model Y & I thought, "hey, he may not be able to use his OWN referral, but he could use MINE" so I asked him about using my referral. When he spoke to Tesla they said it needed to be entered in the original order and could not be added later. In frustration and defiance, he canceled his order to place another order, only now they no longer offer the RWD model AND they don't offer referrals on the Model Y anyway. So this whole thing blew up in his face.
Probably my fault.