Before you go and jump 10K+ into the hole by short selling it, I would figure out what it will take to hold on to it, and just extend your restoration plans by an extra year or 2. Start eating the figurative balogna sandwich for lunch every day, etc, but at least you do own the car, now. There are countless numbers of people that sell a car they own with every intention of buying another one in several years, but that never comes around. Trust me, it will be easier to find money to complete your restoration than it will be to save up enough money to buy another one. As many have said before, you own a highly desirable car. Keep it and take your time to do it right.