In preparing for our site model X were considering what to do with our model S... P85 almost fully loaded 43000 miles. If my calculations are right for a $103600 excluding delivery etc August 2013 car the resale guarantee is $49441. Tesla gave a trade in offer of $49200. Are my calculations correct? If I hold on to the car for 9 more months will I actually get $200 more [provided I limit myself to 2000 miles]. I did get financing with Tesla and still owe $56k... So right now don't have enough liquidity to trade in the S and still buy the X in cash.