Thanks for all the comments, friends! No, I didn’t think to ask the Maryland shop if I could see the brake pads. Next time… They agreed to pass my car inspection but strongly urged me to get them replaced within the next 3K miles. They didn’t push me to have the repair done at their shop. My gut feeling is that these fellows were legit, but I thought I’d ask just in case. To pass inspection I only had to replace the very worn-out windshield wipers. Okay, now that y’all mention it, I did indeed traverse three mountain ranges: a smaller range in southern California, the Rockies and the Appalachian ranges. It’s quite possible that my brake pads were of the cheap variety, like was hypothesized. I didn’t ride the brake petal; in fact, much of the time I sat cross-legged, when there were no other vehicles around. Not sure if my brake calipers were sticky, but the fact that only the front brake pads needed replacing makes me guess that either the pre-trip shop was incorrect, or I really did wear them out during the trip. Thanks, y’all!!! 