Every major change Tesla has made to the Model S throughout the years

Autopilot became an add-on option in September 2014. By the end of the year, all new Model S cars included the camera, radar, and ultrasonic sensor hardware necessary for the addition. The functionality could be activated at any time for an additional fee.

The company also released the first dual-electric motor production car in the Model S in October 2014: the P85D. Tesla claimed that having an electric motor on each axle allowed for better traction and longer battery range.

The Executive Rear Seats option was added as another tier to the Premium Interior Package, according to Car and Driver. The ERS provided two captain's chair-style rear seats with two-zone heaters and controls that allowed passengers to adjust media, climate, and panoramic roof settings with the Tesla app.

The new Ludicrous Mode brought the zero-to-60 time down from 3.1 seconds to 2.8 seconds, according to Motor Trend. This option came with a $10,000 price tag and was only available for the new top-of-the-line P90D.

Launch mode was also introduced as a new function and allowed for quicker acceleration from the starting line, according to Electrek.

Tesla also released a new 70-kWh battery in the Model S 70D, which replaced 60kWh version, according to the Green Car Reports.

A few aesthetic changes to the Model S were made for the 2016 model year.

Tesla removed most of the faux-front grille in 2016, giving the front a cleaner ook. Also, a new vegan interior option was added to the Model S P100D, according to Electrek.

The glass roof became an option for the Model S and was endorsed by Elon Musk on Twitter. The solid glass roof cost about $500 less than the $2,000 panoramic roof. The three roof treatment options then became the painted roof, solid glass roof, or active panoramic roof.

In terms of non-aesthetic changes, the second version of the Autopilot hardware became standard after October 2016, according to Tesla. The "Full Self-Driving Capability" option, which, to date, has not yet been made widely available to the public, had a $3,000 price tag at delivery, according to The Verge.

Tesla improved the quoted Model S zero-to-60 mph performance times, according to Electrek. The Model S 75's time dropped from 5.5 seconds to 4.3, the dual-motor 75D went from 5.2 seconds to 4.2 seconds, and the newer Model S 100D quickened from 4.2 seconds to 4.1 seconds. The 60 kWh version was discontinued.

Further, the range for the 90D improved from 270 miles to 294 miles on a full charge, and the P90D increased from 253 miles to 270 miles. Tesla said hardware and software improvements are to credit for the improved times.

Tesla also started bundling its interior options, Electrek reported and the glass roof and power liftgate became standard, according to Green Car Reports.

Tesla canceled several options in 2018.

The company removed the panoramic sunroof in 2018, according to Electrek. Tesla also removed the black textile interior, rear-facing child seats, and 21" Black Arachnid wheels options. These changes were done to "simplify the product offerings" for the customers, Tesla said.

They also ended the referral program that included lifetime supercharging for the original owner, Electrek reported at the time.

When the Model S was first released, it had a range of 265 miles. The updated Model S Long Range option now has a 370 mile range with the help of a new electric motor, according to Motor Trend. Tesla also added low-rolling-resistance tires.

Tesla dropped the option to outfit the car with a smaller battery, removing the 75 kWh in early 2019, Elon Musk tweeted. This left the base-level battery at 100-kWh.

Also, the adaptive air suspension was upgraded according to a message posted to Tesla's official Twitter account.

Two Model S builds are available right now: the Long Range for $72,115, and the Performance for $92,115.