Road finger 

The act of fingering your girlfriend while she is driving. Opposite of road head

I totally gave my girlfriend road finger while we were driving.

Road finger by iowajoe1 September 5, 2019

road fingers

This is when a someone fingers a women while driving. It's the femlale equivelent to road head. It can be performed by either the driver or the passenger.

Sarah's favorite part of driving though North Dakota was the road fingers.
It seemed only fair that Katie get some road fingers after all the road head she had performed.

road fingers by Jason6025 August 28, 2006