framing fowl
On a mission
I forget where I read it but they recommended asking for the filter before it was installed and putting the date on it with permanent marker. Next time it is changed, ask to see the old filter before they dispose of it so you can check that they actually changed it. Then put the new date on the new one. If the date is on the actual part, you have proof of what is happening. Skr8pn, would that work? We happen to have a great mechanic so I've never done this but it sounds like a logical idea.