The 2017 Model S was the last year before the major MCU2 upgrade and the exterior "facelift" with new front bumper. These cars still use the older MCU1 which is prone to eMMC failure, but they benefit from the most mature version of the original platform with improved build quality.
The main touchscreen unit (MCU1) uses an 8GB eMMC chip that has a finite lifespan, eventually leading to system instability or total failure. Tesla issued a voluntary recall (21V035) to upgrade the chip to 64GB.
The front and rear suspension control arms (wishbones) can develop a loud creaking or squeaking noise, particularly when turning or going over bumps, caused by water ingress into the ball joints.
The air suspension struts or compressor can fail, causing the car to sag or display suspension fault messages.
The flush-fitting motorized handles frequently fail to present or unlatch due to broken internal micro-switches or "paddle" gears.
A yellow tint can develop around the edges of the main touchscreen (MCU1 and early MCU2) due to an adhesive failure in the display stack.