I read one one site and what sounded like the best guess was that the #2576 stood for lbs and the 35 was psi and was directly correlated with the tires. The load rating of 2576lbs at 35 psi air pressure. This is high considering the current drag radial nittos are ~1900lbs max load rating.

This sounded right since each of the videos they have put out have dealt directly with one aspect of the car (first video was weight, this newest video is tires).