Coupons for auto parts are available online, but they are generally tied to a particular mechanic shop and their services instead of a particular part. It is therefore easier to find a coupon for Midas to install a new muffler in your car than a generic coupon to buy one.
Large discount sites, such as RetailMeNot.com or PrintableCouponCode.com, offer a variety of promotions across a wide range of mechanic shops. However, some of the deals may be expired or limited to a particular geographic location and therefore not always accessible. Some shops, such as Midas or Firestone, offer coupons directly on their website or as an incentive to follow them on social media.