The car Kiritsugu used to ride. As a means of transports in Japan, he suitably used his discretion to choose it from a secondhand car dealer.
It has an excellent number of sales in Japan of course, and overseas. He chose it because it’s an economy car that will not stand out anywhere in the world, and because it has power within its capacities.
The initial plan I thought was to make him ride the king of economy cars, the Corolla, but since the combination of Kiritsugu + Corolla suggested a refreshing father at holidays, it was rejected. I also think it suits him too much.

PRISMA material/petit: Encyclopedia of Prisma Illya MOVIE