Right now there are 18 deals from Amazon Resale, formerly Amazon Warehouse Deals, in Automotive › Performance Parts & Accessories › Filters. These are inspected returns and open-box items that Amazon sells and ships itself. WarehouseHunter puts each one next to its current new price, so you can see what you save at a glance.

Brands with the most offers here: Wix, Derale, Edelbrock, Allstar Performance, K&N, Mishimoto. Every item is a one-off, so the stock moves all day and new deals keep arriving.