I can't believe you all are still debating this. The notion that a 3 year old Tesla depreciates only 28% is just nonsense.
Anyone suggesting this 28% has apparently not looked at any used Tesla listings or sold price listings on eBay.
The Model S depreciates just like any other premium car in this price segment. Albeit perhaps slightly better than most. There's nothing else to debate here.
Also the higher end specs depreciate the most. That $160K P100D depreciates about 28% in just the first 12-18 months.