Oil Fill at Gas Station
How the scam works:
As you park to get gas, a station attendant offers to fill it up for you. As they have a full service, he will offer at no cost to wipe your windows or to check your engine oil level. As he does the oil level, he might notify you in a very concerning way that you are so low (in engine oil) that you are even lucky that he got it checked out.
“I could put some oil in for you right now, we have it on special this week”, he says. As you are happy to have it checked out and accept, he will grab a brand new oil plastic bottle from the shelf, take the cap off, show it to you, and stick the neck of the bottle into the oil reservoir of your car.
Once done in 15 seconds, he will throw the 'empty' bottle into a garbage can conveniently located by your car. You see it, pay for the gas and the oil, and off you go. Little do you know that the oil bottle still had a plastic cover on its orifice even after he took the cap off – just like the Gatorade bottles have a plastic lid that you have to peel away after you take the cap off.
The scammer stuck the bottle upside down into your oil reservoir so you can see it, but you didn't realize that the oil didn't pour because of the peel still being there… After he pretended he finished the bottle, threw it into the garbage bin, but then picked it up and put it back on the shelf once you left.
How to avoid:
Fill the oil yourself and try to stay aware of your oil level by checking it yourself every 3-4 weeks or so. If you are not mechanically inclined, just make sure the station attendant (or the mechanic) always does exactly what he says. Get closer, take a look.