The secondary tail light housing attached to the trunk lid of a sixth generation (2017, 2018, 2019 & 2020) Hyundai Elantra contains the reverse (back-up) and inner parking light bulbs. Check out my DIY tutorial for changing the bulbs (with the compatible replacement part numbers) by clicking on the text link or thumbnail image below.
2017-2020 Hyundai Elantra Reverse & Parking Light Bulbs Replacement Guide
