In general, I've found that the high-volume dealers are very much into performing to the script. It's about quick vehicle turnover and $$$. Anything out of the normal throws a kink into their works. Get the Camry in at 9am, change the oil, upsell a brake job, and get it back out that afternoon. Troubleshooting steps tend to result in comments like 'Customer has oversized tires. Replace with stock size and re-test.' If it's an oil change you want then those places are probably fine. If it's something that involves spending time and determining a root cause then I would find a smaller dealer with a more personal touch.