I shopped a lot of times in the internet for auto parts since i live a busy life. with regards to overnight auto parts, they have a huge selection of parts and an user-friendly site.
ads and banners are only a few and lots of information for car n00bs are available. one time, i ordered some fender flares from them and it took about 3 days (they promised to send it in a week) for the parts to arrive. i was happy i was able to receive it early but unfortunately they sent me a wrong part (the fenders are for my dodge, they sent me chevy fenders). i informed them immediately and i was glad that the customer service were really sorry for the order.
they kindly asked me to wait for 24 hrs for the new order to arrive then they asked me to just send the wrong part to their warehouse, free of charge. when my order arrived, they are gave me a gift certificate and discount coupon which i could use for them again as a compensation for the inconvenience they have done to me.
i received a call from their customer service afterwards, apologetic still, inquiring about the arrival of the order and making sure everything was ok.
Judging from my experience as a online shopper, Overnight auto parts would rate "good" as their fault in shipping was more than compensated in their excellent customer service.