Yeah I got a lot of the references it's just not much of the plot to the story was explained in the narrative, and it left me wondering more about the characters. I think more information on the "holy grail war" could've been included in the story and that may have made reading it a little bit more satisfying. Also the classes of the car characters seemed a bit out of place at times for the model of the vehicle, and even though you provided a lot of build up and suspense for it there wasn't one scene that actually included the participants taking part in this race or death-match. The story kind of gave me an F-Zero kind of feeling, but without an actual high speed death battle there wasn't much excitement for the reader to latch on to.
I will add though that I've never heard of or played Fate/Stay, and seems like you may have rushed and maybe omited a lot of possible action to keep it around 2500 words. I too would like to read an extended and more polished version of this in the future, and you definitely deserved the creative writing award you got for dreaming it up.