Everything is expensive without scale. But lidar will be very cost effective, when scaled to millions upon millions of cars annually.
And with scale, there are reasons to optimise, reduce cost, etc. Large volumes of sales draws more research. Research to reduce cost.
Self driving is a long game. Decades.
Lidar production costs have already scaled. Now it need more miniaturization (which will help with production costs even more) and something against diffraction.
To each their own, but it's possible having sensor bumps on your car become a status symbol that indicates you can afford a private driver.
> not sure you can have it on a convertible etc.
Radically different car shapes are possible when human driving never happens or is very rare. Maybe a small van (like a private lounge on wheels, or a train observation car) with a huge panoramic sunroof becomes en vogue.