I'd be interested to trade my late SIG or early P for an early SIG (< #300) and would pay a premium for that trade.
I think he's asking about trading in a car you currently own at the time you purchase the Model S, the same way most people would when they buy a new car at a dealership.
On my MVPA paperwork there is section 4 that deals with trade-ins and related credits. Section 4 has lines for year, make, model, VIN of your trade-in. There is a line for "agreed trade-in value", another for you to divulge any outstanding associated debt and then one for net trade-in value. Other lines include deposit (the $5,000 or $40,000 you paid a long time ago), cash, and other. These numbers are added up and then subtracted from the sale price to yield what is to be paid upon delivery. When I asked about the trade-in value, the salesman told me that the value would be determined by a yet unindentified third party. The quote would not be valid for very long, so will not even be offered until just before delivery of your car. I was referred to Auto Nation to get an "idea" of my car's value. Back in the fine print there is a complete section covering your trade-in and how you warrant that it is free and clear of any encumberences, that it has never been a taxi or police car, etc.
(MarkV | May 19, 2012)