Review on OEMTOOLS 87024 Oil Funnel: No-Spill Design for Toyota, Lexus, VW, and Mercedes Vehicles - Efficient Filler Neck Screw-In - Save Time with Hard-to-Miss Green Color! by Damion Pasquale

This is by far the best funnel I have ever had! Don't worry about the funnel falling out of the oil filler neck as it snaps in place like a cap and you can leave a liter in! Also features 0-rings to ensure no leaks when filling! I like that the bottom is transparent, you can see when a liter of oil drips. The only downside is that you need a separate sensor for each make of your vehicle. In my opinion, changing the oil yourself is fine as you don't have to clean up any funnel stains that fall in or out of the throat.