Rock Auto for stuff you need next week. AutoZone for common stuff you need immediately. O’Reilly for uncommon stuff you need immediately. eBay for used OEM stuff.

Rock Auto is cheap but you’ll have to wait for shipping. AutoZone is not too expensive but won’t have rarer items. O’Reilly seems to warehouse almost anything but is more expensive. And if you have no other choice, NAPA.

Had a starter die on me. Autozone had one in stock in store nearby and I had the car fixed that day.

I had a rat chew some wiring all the way down to the connector on a Saturday evening. Rock Auto carried a replacement, but I couldn’t wait for a week. AutoZone didn’t carry it at all. But O’Reilly was able to get the part to a store by noon the next day, and I had the car working by evening.