Advance Auto Parts in Grayson is a local automotive parts store offering a variety of aftermarket products and services. They provide free services such as battery testing, engine code scanning, and installations with purchases. Customers appreciate the loyalty program, Speed Perks, which allows them to earn points for discounts. Many reviews highlight the helpfulness of the staff, particularly mentioning employees like Mandy, Jennifer, Rebecca, and Chris. They are praised for going above and beyond to assist customers, whether it's finding the right parts or explaining technical issues in simple terms. One customer noted Chris's exceptional service when diagnosing a check engine light, emphasizing his willingness to help. However, some reviews express frustration with the lack of knowledgeable staff on certain occasions, and there was a mention of inconsistent services, such as diagnostics that were previously offered but were not available at the time of visit. Despite these concerns, the overall sentiment reflects a strong appreciation for the friendly and attentive service provided by the team at this Advance Auto Parts location.