I believe I am qualified to answer these questions. I’ve worked in many Design Studios including that of McLaren, Jaguar, Land Rover, Bentley etc. I’ve worked in initial design all the way to manufacturing. So now that we’ve settled that.
One key thing to remember is from the day the design director first puts his idea on paper to the day Job 1 or first customer car is produced it will take 5 - 10 years. Honestly speaking, I’ve never worked on any project that has run on the projected time plan. Honestly never. Doesn't matter how many cars, if it’s 100 McLarens or 30,000 Land Rovers. No project I’ve worked on ever ran as per the plan. It was always delayed.
When we work to design a car, we actually have to design a car for the future. So a design produced today will be out for people to buy almost 10 years later. So you see concepts looking all futuristic. But by the time it’s released they look more realistic.
When a car is designed, it’s designed by designers. They are artists - pure artists, not engineers. Then the designs move to studio engineers who then make everything feasible and a reality. So it’s always a battle between designers and engineers. Engineers want reality and designers want, well a beautiful car. They seldom care about budget and other marketing constraints.
To be completely strict to your question, “how long does it take for the designer to design a car?” well not long at all, a few hours to a week. Then it’s passed on to the rest of the design team to add the details followed by an approval of the design director. Then we build clay models from small scale then later a full scale. Interior design cubes are also made. Then scanned with a 3D scanner then the digital process starts. This is the most painstaking process because a design that usually looks nice and amazing is usually very hard to produce. Not impossible but very hard. If it costs too much then there is a compromise between the engineers and the designers.
After surfaces are confirmed then the actual engineering goes, i.e., things underneath the car. Packaging all the components and making sure they work etc. Don't forget many companies run design and engineering side by side. That doesn't always work but it’s a good time saver. But after following all these steps from, Design - Engineering - Packaging - Testing - Release - Job 1 you get a car that was designed 10 years ago.
I’ve obviously missed out a lot of key aspects between the design and release process. Such as virtual testing, virtual builds, crash testing (a lot of design changes after crash testing), dynamic testing, on road tests (things vibrating cause issues), noise and rattle, cost down events, build issues. Honestly, the list can go on forever.
And after all that effort, the world gets to see the car that the design director once imagined and most of the time it's quite different to what the actual car is:
The list can go on, but a lot of these cars also do look the same as the concept.
Wow what a response, lol guys I’m so flattered. I just started on Quora and thank you so much for this. More than 1.5k upvotes. Thank you so much. I just poured a bit of my mind out on an answer and so thankful for such supportive and generous comments. Honestly I can talk about cars all day long. I look forward to keeping this up and hopefully answer more and hear more from you guys. Another thing I find that I love is the comment section. Listening to people and reading their thoughts and small discussions, love it all. Please keep the thoughts and responses coming and I’d love to keep this up. Once again guys thank you and I’m so humbled by the love support.