Usually, seat belts are just a onetime use product. And normally you need to replace them with a new part. The price can be way more than a $1000 per each seat belt. So, the next step on your list is to check used seat belts; those can be way cheaper but the reason why it is bad option, because sometimes salvage yards sell blown seat belts, without inspecting them, so you end up wasting time and keep looking for another ones.
And there is a way better alternative, you can get your seat belts repaired, no matter if it's Audi seat belts or Nissan seat belts, we can repair any seat belts in 24 hours.
You end up saving money and saving time, because you are guaranteed to receive 100% working seat belts.