In a report by One Click Retail, who collects sales data for the world’s top ecommerce marketplaces, Amazon recorded $2.4 billion in automotive related sales based on just their first-party sellers. The company experienced a 16% YoY growth, and in the first half of 2017 trucking accessories at $185 million and towing/towing accessories at $70 million topped the U.S. selling categories.

Amazon has been selling automotive parts and accessories for years, but last year the company launched their own car research site and a specific parts marketplace. These new features allow shoppers to punch in their make and model to search for the correct parts.

The report also notes that two major trends in automotive aftermarket sales are that owners of older cars focus on more maintenance products, while new car owners tend to invest in appearance products. As vehicles on the road age, the underhood and undercar replacement parts segment of Amazon has generated nearly $300 million in sales during the first two quarters of 2017 alone, a growth of 20% YoY.