Owners of an early-build Tesla Model 3 variant may soon be able to add a basic version of Autopilot via an in-app upgrade.

Typically for Tesla, this announcement was made by CEO Elon Musk on Twitter. When a Twitter user asked Musk if owners of the discontinued rear-wheel drive Model 3 Long Range variant would ever be able to purchase Autopilot, Musk replied in the affirmative.

"Oh sure, good point. Will discuss with team & make available to buy in Tesla app," Musk said in a tweet (via Teslarati).

The upgrade would likely apply to cars built before the rollout of Tesla's current Hardware 3 chipset in early 2019.

Hardware 3, together with an Enhanced Autopilot package, brought several new features, including Enhanced Summon parking system, that likely can't be deployed to early-build cars.

Tesla has spawned a confusing array of driver-assist systems, spanning Autopilot, Enhanced Autopilot, and Full Self Driving (a misleading name, as all Tesla production cars still require an attentive human driver behind the wheel).

It's unclear where a basic retrofit Autopilot system for the early Model 3 would land on this scale of functionality

Another question is price. Tesla traditionally charges customers more to activate Autopilot after purchase than if it is ordered with the car.

The Twitter conversation only mentioned the Long Range model with rear-wheel drive, which is no longer in production. Long Range models are now all-wheel drive only.

It remains to be seen whether an Autopilot upgrade will be made available for the rear-wheel drive Model 3 Standard Range, the $35,000 entry-level version that currently exists as an off-menu option.