This illustration is done entirely by hand. It’s by the legendary commercial artists Fitz and Van in 1968.
As far as I can guess the picture was constructed as follows: a stripey wash of pale was applied to a dark sheet of Canson paper. One way to do this is to grind up a pastel stick, mix it with talc and dab it with a cotton wool tuft soaked in lighter fuel. You then wipe it quickly across the page. Then the background figures were added. Some masking and airbrush work was done for the main areas of colour. The details may have been applied with pencil or using acrylic paint and brushes.
Meanwhile, the car was laid out on another sheet. The lighter areas were masked off and sprayed (the light blue). I don’t know how the interior was done: perhaps black Magic Marker. The chrome featured a lot of fiddly micro-spraying (I think) and is simply exquisitely handled. Notice the highlights down the body side as well, picking out the flaring around the wheel arches.
When the car and background were ready the car was cut out and laid over the background.
Quite simply this is remarkable work, incredibly evocative then and now.