Amazon calculates a product's star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers and factors that establish reviewer trustworthiness.
This is an awesome product. Even though the description says micro hair line scratches its much more than that, just need some more elbow grease to get it done. I had all sorts of scratches for which the dealer quoted 15k to fix. Though it didn't work for wider & deeper scratches, 90% of the number of scratches are gone and car is sparkling. (how long will it last is yet to see) Loved it.