BMW has had lane assist (I believe standard) for a few years now. As others above have said, it gives resistance and visible feedback with varying degrees of force if you try to change lanes without a blinker. Many others makes now do as well.
Essentially, in a 2018 or newer model BMW it is a pain in the ass to change lanes - even on an empty road - if you don’t use a blinker. And it probably snitches on you to your insurance company if you frequently make the light come on.
As for the lowered 2011 3 series with the loud exhaust and not quite right looking M badges passing you in a cloud of strawberry mountain dew flavored vapor, well… yeah what do you expect. The forest of little tree air fresheners makes it hard to see through the rear view anyway.
Japan was invading China.
But this is clearly fake and connected to the month of June.
Anon probably read a story about this happening and assumed the heir of the protagonist. Then used online for attention and group feedback on his projection that hiding in a cave is somehow based.
They are probably in that cave right now.