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.
Mythic Quest CEO Level Achieved.
Next up, stories of inappropriate conduct leak and somebody tiger’s a camero.