Someone who saves a huge amount on their car insurance because they own such a vehicle (and therefore should never be subjecting the insurance company to claims caused by their impaired driving) I assume?

People that get convicted of DUIs and want to keep their license. We already have modifications to cars that require people to blow into to start their car, this seems like the logical next step in that.

If it catches me dozing off during long drive, that's a perk in my view.

rich parents will buy them as high-school graduation presents. It's a very, very tiny market.