That is a consideration. The problem is the 5 quart containers will never fit in the engine compartment. It would require some elaborate twisting to go from the oil tank, around the hinge and fender and then upright. I doubt it would steong enough to hold the container.
And even with the one quart funnel, I expect at first with 20-50 I will need to pour carefully, and then once the main amount of volume is in, then push the oil container into the funnel.
It does have a larger neck than the other funnels I have, but until my 911 burns another 1/2 quart, I can't test it in real word conditions.
The neck is just under an inch wide on my funnel.
On the 3D design thread there are some funnels that might work for you. I designed this one to fit my needs.
I have shipped out three so far, so I guess I can't go order a new 911 just yet.
I am only making them available as a service to other 3.2 Carrera owners that want a better way to add oil, and they don't have a 3D printer handy.