An extraordinarily generous taxi service.
Indispensable for getting to the Einzbern Forest, but after you get dropped off, the only way back to town is walking. Ugh.
Of course, if you ask me there’s something seriously wrong with a taxi that doesn’t have any problems taking students out into the woods in the middle of the night.
By the way, when Kotomine arranged for a car and driver in the Sakura route, he didn’t go through the Association or the Church, but rather used his own personal network of connections.
In the plotting stage, the same conversation occurred after agreeing to cooperate with Kotomine:

“So how are you going to help me?”
“Hm. Our method of transportation, to start out with.”

However, after that the screen would black out, and a deep rumbling sound effect would play as Kotomine pulled up on a Harley!
…Well, it’s true that I might have gotten excited and written something like that down at one point, but eventually I regained my composure and the scene took on its current form.
At any rate, the trunk of the car was fully loaded with dangerous weapons, up to and including submachine guns. Pe-Pe-Sha!

Fate/side material: Fate Encyclopedia