The Star Rating feature in Need for Speed: Underground and Need for Speed: Underground 2 is a ranking system that rates the visual appearance of the player's car. In the first Underground, it is referred to as 'Star Reputation', whilst in Underground 2, it has been renamed to 'Visual Rating'.
Adding a visual upgrade that has a higher rating than the one it replaces will rank the player's car higher within the Star Rating system. Points will be removed for installing a lower rating part or removing a part. In the first Underground, the Star Reputation system goes up to 5 stars, and has been increased to a 10 star rating in Underground 2. Unique parts add a higher star rating than any regular visual upgrade of the same category.
High Star Ratings are required for unlocking magazine cover opportunities and unique upgrades in the first Underground. In Underground 2, they are required for unlocking DVD cover opportunities as part of sponsor contracts.