It depends on who you want to make the car more valuable to.
On one hand, you only live once and why let the car sit in the garage, on the other, you are driving dollars off it's value for every mile. What is a guy to do??
GTFUN,
The first thing you need to do is realize that.....
1. 50 years from now we will all be dead.
2. If you are successful enough to have acquired a Ford GT, the state will confiscate the bulk of the wealth that you still possess upon your death.
3. Every day of your existence brings you a day closer to your demise.
4. Deathbed regrets consists almost exclusively of angst over those things we did not do when we had the chance. I've never heard a dying man express to his family that, "I sure wish we hadn't taken all those vacations together and kept the money in the bank instead".
5. If you preserve your car in pristine shape for the enjoyment of it's next owner, you have turned it into a non yielding investment that requires annual insurance, registration, and maintenance expenses to boot.
6. If you're not going to drive it, you'll not derive any more benefit from it than those who admire it when you park it at your local cars and coffee. The admirers have a better deal however, as they don't have to pay for it.
In short.......drive the damn car. In time, the experiences you share with your Ford GT will leave a few battle scars on it. But those experiences will leave an even more indelible impression upon you. Indeed, the same minor wear and tear that will make your car slightly less valuable to a future purchaser, will make it priceless to you.
At least, that's my take on it.
Chip