These are the same Scribner heavy duty funnels used by pro racers, motorcyclists and off roaders worldwide. All have an anti-splash lip around the top. A filter can be added. AND, they are available in all the neat jug colors. Made from the same tough LLDPE polyethylene as the jugs, they are resistant to most everything and last forever - Stay away from those imitations that don't.
This has worked great in several of my BMWs, several E30s and an E36M3.
The only issue I have is that it could use something to stabilize it in the filler neck. If not careful it will tip sideways on my BMWs.
It may work without issue on Porsches.