Sketching free-hand showing excellent skills & talent is extremely important to be a designer.
In a Design Process, to develop a project, sketching is the first important step to make, drawing on paper our ideas (ideation stage or brainstorming step) will give any designer a passional and fun way to look for ideas and also to do it in a more efficient way in terms of timing. If we know how to draw it will be easier to see on paper our ideas.
Any project has its Design Process and Design Planning (how long will it take to make the project according to company’s time to market plan); to perform correctly every step of this process has a given time that we (designers) must respect.
You understand that if you do not sketch well or think that you can easily jump steps to go directly to sketch modeling you are making a big mistake! The reason is simple: it will take you a lot longer to respect the Design Process Timing (specially in Car Design).