"Preservation," as opposed to full-on "restoration," is a relatively recent trend for car collectors, said Hammers.
A couple of decades ago, a barn find car would have been restored, or returned as close as possible to the way it would have looked the day it left the factory. (Or, in some extreme cases, even better.)
"In the '70s and '80s, everything got restored," said Hammers.
In a preserved car, the clock is simply stopped, its true age is respected and there's no attempt to make it look like new.
With Ford's new Mustang set to be unveiled on December 5th and the car's 50th anniversary in 2014, we asked collector car experts to tell us what the most important Mustangs through the years have been.