Saw gas leaking after a fill-up and traced it to the emissions canister that seats into the tank. It wasn't seated all the way. Popped it in and solved my problem. I find it hard to believe that your system is showing a false leak. Sounds like lazy mechanics trying to avoid a small but tough problem to troubleshoot.

 

2012 Mustang owner. I always find gas stain on the body of the car just underneath the gas cap area. It looks as if it's an overflow but I usually only round off to the nearest dollar or half dollar. Anyone have any answers why this happens? Car is white and the stain is unsightly. Don't want the paint damage in the future.

 

evap systems are easy to troubleshoot (if youre smart enough to troubleshoot to start with lol) if a shop says that they cant figure out an evap problem, its time to find a new shop. a smoke machine, and a scan tool, and any problem can be diagnosed within an hour.