This is a how-to for the 2019-2022 (Gen 2) Hyundai Veloster N engine cabin air filter. This is another very straightforward job, and I imagine it would be the same for non-N Velosters of this gen as well. No tools required, but maybe one optional.
Items/Tools Required:
- Just the cabin air filter!
- Recommended: pliers
1. Open and empty the glove box. Locate the rubber fittings on each end, twist counter-clockwise, and pull out. 
2. Remove the other side as well. 
3. After removing the two end plugs, the glove box will lower but is still connected by this arm. I’ve seen some people pinch this closed first, but I had to use the pliers here. Once you squeeze the clip, it can be disconnected from the arm. 
4. Lowering farther will expose the cabin air filter housing. 
5. The housing opens by detaching the clip on the right and swinging the door open, as shown. This will expose the cabin air filter. 
6. Swap cabin air filters, making sure to follow their air flow pattern, and reverse the steps to wrap it up!
QL Motorsport & Car Journal 