He said LIDAR is expensive, it's not solid state right now,
There are solid state versions of LIDAR, including phased arrays (similar to how radar can be made without a moving dish/antenna to scan an area). Didn't look up relative costs.
Whether they are automotive-level reliable I don't know, as I haven't had one in hand, or looked up testing on them, but some of the companies making them do so specifically for automotive purposes, including self-driving cars.
so not automotive level reliable, and it works in the visual spectrum. Meaning if you can't see it with cameras, LIDAR won't see it either either.
The few hobby-level LIDARs I have investigated for my own uses are infrared, outside the visual spectrum. At least some of the solid state ones are as well (possibly all of them; I didn't investigate).
It is possible that it's still within the spectrum of the CCDs commonly used on visual-spectrum cameras, but most of those filter NIR and IR out by means of a coated glass over or behind the optics.
I suspect but haven't researched that within cameras used for automated systems these filters are not used, so that onboard NIR and IR light sources can be used with them in addition to normal ambient lighting, to provide a bright light source that will not affect human drivers / operators / etc. that are near the automated system.
The disadvantage of light below the visual spectrum is that it carries less information for the same bandwidth, but UV and higher lasers and light sources above the visual spectrum can be detrimental to living eyes and tissues so they are not typically used outside of closed systems.
(snip) Musk understands better than most that to succeed the product needs good aesthetics,
That isn't self-evident from assorted visual design choices we've seen.
