Enlarge / Tesla's "Full Self Driving" system just got a third cheaper. (credit: Edie Leong for The Washington Post via Getty Images)

Tesla has dropped the price of its controversial "Full Self Driving" partially automated driver assist. Last week, getting access to FSD would cost you $12,000—today, it's a third cheaper at $8,000. Alternatively, customers can subscribe to the feature for $99 a month.

Tesla has bet heavily on FSD for the future of the company. It's one of two partially automated driving systems offered by Tesla—Autopilot is the older and less-capable system. FSD includes features such as auto lane changes, auto parking, the ability to summon the car from its parking space, and lane keeping (Autosteer in Tesla-speak) on surface streets.

Tesla claims that "[y]our car will be able to drive itself almost anywhere with minimal driver intervention and will continuously improve," but then also notes that "[t]he currently enabled features require active driver supervision and do not make the vehicle autonomous."