To equalize tread wear, HYUNDAI recommends that the tires be rotated every 7,500 miles (12,000 km) or sooner if irregular wear develops.
During rotation, check the tires for correct balance.
When rotating tires, check for uneven wear and damage. Abnormal wear is usually caused by incorrect tire pressure, improper wheel alignment, outof- balance wheels, severe braking or severe cornering. Look for bumps or bulges in the tread or side of tire. Replace the tire if you find either of these conditions. Replace the tire if fabric or cord is visible. After rotation, be sure to bring the front and rear tire pressures to specification and check lug nut tightness (proper torque is 79~94 lbf·ft [11~13 kgf·m]).

Disc brake pads should be inspected for wear whenever tires are rotated.
Information
Tires that are asymmetrical or directional can only be installed on the wheel in one direction. The outside and inside of an asymmetrical tire is not easily distinguishable. Pay careful attention to the markings on the sidewalls of the tires, noting the "outside" marking and also the rotating direction before installing them on the vehicle.
WARNING
Check Tire Inflation Pressure
Wheel Alignment and Tire BalanceHyundai Elantra AD (2016-2020) Service Manual: Mode Control Actuator Repair procedures
Inspection
1.
Turn the ignition switch OFF.
2.
Disconnect the mode control actuator connector.
3.
Verify that the mode control actuator operates to the defrost mode when connecting 12V to terminal 3 and grounding terminal 4.
Verify that the mode control actuator operates to the vent mod ...
Hyundai Elantra AD (2016-2020) Owners Manual: Detecting Sensor. Warning message
The rear radars are located inside the rear bumper for detecting the side and
rear areas. Always keep the rear bumper clean for proper operation of the system.
NOTICE
The system may not work properly when the bumper has been damaged, or
if the rear bumper has been replaced or repaired.
...