Those adapters are cool. But I'm way too cheap for that. My 2016 Mercedes V6 had a sensor just inside the filler opening (go figure that engineering feat out) so I made a funnel to do the job.
I used a 2 liter Coke bottle, cut a notch out of the spout that would go beside the sensor, and BAM! Perfect fit, now the sensor makes it non slip, and the large opening makes it drip free.