I know it's not like SR2 where you can just add, say, SWAT kneepads or Sunshine's coat to the store, but if you've played to the end you should notice that two of the unlockable outfits are "sex doll" and "toilet", and they're obviously different character models. The "toilet" doesn't even have arms! So my thought is, maybe someone who actually knows how to do this could create an "outfit" that changes the player's model to, say, the Deckers specialist, or Shaundi, or Oleg, or Gat, or whatever. I would do it myself, but I can't figure out how those two outfits manage it.