Doing up cars is rather an expensive hobby usually enjoyed by males who actually can't afford it. What starts as a simple paint and bolt-on project will invariably expand to a total tear-down, ground-up restoration with little, if any, encouragement1.
Conjecture surrounds the generalities of this hobby's history. It's believed that most who take up this hobby gained their interest in early childhood. It begins as an infatuation with all things shiny and fast. As the eventual hobbyists grow older, they discover plastic scale models which only reinforces their desire to have a go at the real thing.
Sometime in the teenage years, the hobbyists typically purchase their first car. Many long hours are spent repairing and modifying it to suit their desires. Years pass, and the proto-hobbyist discovers that he has learned quite a bit about a rather long list of various makes and models of automobile. He soon grows weary of working on them, though, as his mechanical skills become merely a method to keep wheels on the road, and no longer for pure pleasure. As soon as he's able to afford it, he begins to hire people to do these things. Eventually he reaches an age and level of income at which he does not have to work on any aspect of an automobile.
Old memories die hard, though. The fingers itch for the feel of cold steel in the hands, and the proto-hobbyist longs for the feeling of hot grease in the hair. The lingering memories of primer and lacquer thinner make the heart race. All it takes is the slightest hint of encouragement, and the hobbyist is off and running! A short time later, he has several projects underway simultaneously, and a tinkerer's garage that would be the envy of most professionals. Let's not forget the rather bewildered neighbours who can only scratch their heads in wonder as the hobbyist drags in the backyard junkers, only to strip them for their parts and have their empty hulls hauled off to the nearest scrapyard.
There are many variations on this hobby but two are considered to be in opposition: full restoration and hot rods.
This is considered, by some, to be an art form. The objective is to bring a vehicle back to its original showroom condition. While there are various levels within this realm, the most impressive and most expensive is the frame-off, ground-up, matching numbers restoration. In this, one completely disassembles the car, boxes up the parts and proceeds to clean, repair and replace all parts, including the nuts and bolts, to new factory specifications. The pre-requisite for this procedure is to start with an automobile in fairly good condition, which still has the original drivetrain2 in it.
Once completed, these machines are a wonderful sight to behold but their days on the road are over. They become what are referred to as 'trailer queens' - true museum pieces which are hauled from show to show, gathering trophies and trade magazine write-ups wherever they may be unloaded.
This is the other end of the automotive hobby spectrum. While a hot rod need not be as expensive as a restoration project, it can be. In this arena, speed and handling are the goals. Modification is not frowned upon - in fact it's highly encouraged. The auto-builder is not attempting to replicate the manufacturers work, he is doing his level best to improve upon it.
The methods used range from modest upgrades to existing systems, to starting from a bare body, and fabricating more modern systems one would like to see in it. These fabricated rods can become rather exotic, sometimes to the point that the original car is no longer recognizable.
Neither of these extremes are warranted to enjoy the beauty and fascination of vintage automobiles. The only things one truly needs are good mechanical skills, a good automotive repair guide, and a healthy dose of desire.