I have one of those overly difficult cars that were assembled so you can't DIY. I went here to get a get a free battery and alternator test so that I could take it to the dealer and not get charged the $150 diagnostic fee. A guy came from the back with his kit, tested the battery, said it was "shot," alternator was fine, and started loosing bolts. It took about an hour but he replaced my battery on the spot and likely saved me a couple hundred bucks.