How do I fix the door closing mechanism on an Audi 80?

My Audi 80's door doesn't close properly as it seems to get stuck on something before fully closing. I've tried WD-40 but it only helps temporarily, what can I do to fix it?

Check and clean the door latch mechanism and the door striker plate for any accumulated dirt or debris. Sometimes, simply clearing them out can make a huge difference in how the door closes.

Adjust the striker plate to ensure that it is aligned with the door latch. If it is even slightly off, it can cause the door to stick and not close properly. A few small adjustments can make a big difference.