Running at 2000FPS in low light (and getting meaningful data at that sensor size) is also impossible to begin with. Even if you can do constant 60, you're in good shape.
2000 can be good for doing multiexposure and maybe detecting fine movement, but assuming that everything running 2000FPS (and processing 16000 frames/sec) is not a simple thing, esp, if you're running in an uncontrolled and chaotic environment.
I was about to comment the same, 2k FPS means a maximum shutter speed of 1/2000, you need a lot of light to capture an image this quickly, in low light conditions it's simply impossible to capture enough light even if using very high end optics and sensors.
I don't know the specifics, maybe they are timing individual cameras in a way they achieve 2000fps with a crisp image in each camera and merging them together. Or maybe they are using some MIT tech that was able to capture super low light conditions.
Being able to capture in super low light conditions is dependent on two things. 1. Your sensor's noise floor, 2. The number of photons you can get per unit time.
First one is dependent on the manufacturing process, and the second one is dependent on your sensor size.
Currently, the leading sensor manufacturers (namely Sony Semiconductor and Canon) are doing very low noise sensors. However, to get both these low noise levels and convincing images needs full frame sensors, at least. APS-C can somewhat close, but it can't be there (because physics).
Even in that case, you can't do 2000FPS and get meaningful images from every one of them.
There's no way that a Tesla car cam sports full frame or APS-C sensors.
AFAIK Sony and Canon are still using some ancient manufacturing process for sensors as chips have the priority and if Tesla has access to e.g. 5nm process for manufacturing sensors that would drastically expand possibilities. Also you bypassed the possibility of timing multiple sensors separately to achieve 2000fps.
The reason sensor manufacturers use "seemingly ancient" (i.e. huge feature sizes) processes in their sensors is you really don't need a more advanced process like in processors.
When you manufacture something which computes, power consumption and internal noise improvement is more drastic with improved manufacturing processes. When you are measuring something, you don't need or want too small pixels or features to begin with.
So having a small gigapixel sensor just because your process allows creates more disadvantage over having a sensor same size with a lower resolution, from light capturing angle. So, low-light sensitivity and resolution is a trade-off.
Back-illuminated sensors used by all contemporary cameras created this leap rather than reducing feature size via improved processes. You already pack the sensor as dense as possible (you don't want gaps or "smaller" pixels w/o increasing resolution either), and moving data/power plane away from pixels is the biggest contributor to noise in the sensor.
See the link [0]. Top left image is full frame, top right is APS-C, bottom left is M4/3, and bottom right is full frame / high-res (60+MP) sensors.
When you look at the images, smaller the sensor, worse the noise performance. When you compare full-size images of top left to bottom right, top left image is better in terms of noise. I selected RAW to surface "what sensor sees" The selected spot is the darkest point in that scene.
You can select JPEG to see what in camera image processing does to these images. Shutter speed is around 1/40s and ISO is fixed at 12800 since it's the de-facto standard for night photography.
> Also you bypassed the possibility of timing multiple sensors separately to achieve 2000fps.
Working on an image which doesn't reflect real world is a bit dangerous, isn't it?
2000 can be good for doing multiexposure and maybe detecting fine movement, but assuming that everything running 2000FPS (and processing 16000 frames/sec) is not a simple thing, esp, if you're running in an uncontrolled and chaotic environment.