There’s no direct answer to this question, but unlike what you'll see on TV, restoring a car will certainly take longer than a week.
There are many factors to consider, but here are a few to consider:
Is your car a popular model, and are there a lot of replacement parts for it?
Are the replacement parts of good quality?
What make is your car? Ford, Chevrolet, Dodge, Oldsmobile, Pontiac, etc. All cars are built differently; some may take longer to repair than others.
Is your car a Convertible, Hardtop, Coupe, or Sedan? Compared to a Hardtop, a Chevrolet Impala convertible has far less surface area that needs to be primed and blocked multiple times. The convertible may also have less roof area, but it will usually have badly damaged floors and more complex braces that need to be fabricated to hold the car together. Consequently, this may require more fabrication or panel replacement that wouldn’t have been needed for a hardtop.
When was your car built? Pre-war cars are made with thicker steel; most are actually "overbuilt." Some of these cars may have wood framework inside, which is often rotted and needs to be replaced. After the war, mass production was in full swing, and by the mid-1950s, hand-built cars were almost fully a thing of the past. With factory assembly lines and mass production, some replacement parts are much easier to obtain for these later models.
Do you want your restoration to be completely original or have custom features? Custom craftsmanship always takes time, and it becomes difficult to determine how long some projects will take.
Communication at each step of the process is the key to customer satisfaction. Think about taking every little piece off your car, cleaning and detailing each part, painting or polishing each part, then putting each and every part back on the car. It can take a while to do it right.
If the job is rushed and corners are cut, it won't be long before all of your problems are back, and that spot of rust may be worse than before.
If it’s a project you intend to keep, it’s less expensive to do it the right way once than to do it repeatedly.
