Everyone does this. Everyone wants you to keep paying for a vehicle.
Ever since I fully paid off my Miata 5yrs ago, the persistent mail, email and a few phone calls asking me if I want to trade it in for a new model has been like clock work.
After visiting the Lawrence delivery center this a few weekends ago, I'm a little convinced the place operates kinda like a cult. Don't get me wrong, I admire the enthusiasm, but to have owners just linger around the lobby answering questions out of their own time and free will?! Nope, I dont' buy that. They're there to nudge you into a new Tesla whether you're ready for it or not.
I will gladly wait to see what comes of the Model 3. My present car can last me another year or 2 easily. Unless they somehow offer a Model S for the price of the 3, I'll be patiently waiting for my turn at obtaining a Model 3.