When using the rear center seat belt, the buckle with the "CENTER" mark must be used.
Hyundai Elantra AD (2016-2020) Service Manual: Speaker Repair procedures
Inspection
1.
Troubleshooting for Speaker
(1)
Basic inspection of speaker
Inspect the sound from speaker after verifying that the
speaker mounting screws is removed and the wiring connector is connected
precisely to remove vibration transmitted from body trims and
surrounding parts.
...
Hyundai Elantra AD (2016-2020) Service Manual: Fuel Filter Repair procedures
Removal
1.
Remove the fuel pump.
(Refer to Fuel Delivery System - "Fuel Pump")
2.
Disconnect the electric pump wiring connector (A) and the fuel sender connector (B).
3.
Remove the head assembly (A) after releasing the cushion fixing hooks.
4.
Disconnect the fuel tube quick-connect ...