That guy is a legend, I've just been through the Parkers guide for even the most modern diesel fiesta and they are all over 10 seconds to 60. The fastest diesel fiesta I found was 11.2 seconds. As one of the comments says, unless there's a Saturn 5 booster rocket in there, it ain't happening.
"My first attempt was 7.5. And it didn't get a very good start. I did to others. My best was like 5.5"