As noted in other comments, other major carmakers can complete a car in about 1-3 minutes, not including customization tasks like painting.

So 37 minutes of rework per vehicle means that they're less than 5% as efficient as their competitors, despite the massive investments they've made their factory line. It's indicative of serious production issues and will be a major roadblock to scaling future production, since it means that if they don't solve the production issues leading to the rework, then they would need to spend 20x what their competitors to achieve the same volume of production.

EDIT: The 3 minutes is time-between cars. Each car takes 17-18 hours to get through the entire line. So 37 additional minutes is still pretty bad, but it's not 20x as inefficient on a time-basis. However, given the number of workers at the Tesla factory, they are still 20x as inefficient on a labor basis.