Last week I brought in my Ford F150 truck in because we noticed a very small leak under the truck. Due to the minimal leak, they suggested an under-carriage wash and put in a fluorescent dye to help locate the source. They asked me to come back a few days later to fix.
Today, I brought it back in. The source seems to be slightly over-filled transmission fluid which is escaping from an upper "vent" - only occurring because of the recent hot weather. They will check it again when I bring the truck in for an oil change in about a month. (They recommended to leave the transmission fluid level as is because there is no easy/inexpensive way to remove a little. It would require "dropping the pan" which would waste a lot of transmission fluid.)
Many repair places would have tried to push an expensive (and apparently unnecessary) fix. They did not. I'm very impressed.