What's the best lens?

No such "preferred" lens exists or ever will exist. You first need to know the distance from the subject and the framing you want to use, When you know those factors, you will know the range of lenses that may be useful. For some people, a wide angle lens may be most appropriate, or something with a narrower field of view. Only experience with actual automotive photography will help you make that decision.

For example: images from auto shows using a Canon 18-200mm IS lens.

Byte size: ZERO | Content warning: NOT AN IMAGE

Focal Length: 40.0mm
Aperture: f/7.1
Exposure Time: 0.0080 s (1/125)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: program (Auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB

Byte size: ZERO | Content warning: NOT AN IMAGE

Focal Length: 18.0mm
Aperture: f/7.1
Exposure Time: 0.0080 s (1/125)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: program (Auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB

Byte size: ZERO | Content warning: NOT AN IMAGE

Focal Length: 200.0mm
Aperture: f/5.6
Exposure Time: 0.0040 s (1/250)
ISO equiv: 250
Exposure Bias: none
Metering Mode: Partial
Exposure: program (Auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB

These images, which are one person's interpretation of automotive imaging, come from three distances and use substantially different fields of view available from a single lens. However, another photographer will choose different framing and distances, which will require different fields of view. Unless your goal is to strictly imitate what others do, you'll need to determine the type of images you want to create. Which, again is why no such "preferred" lens exists or ever will exist.