The Nuclengine HS Model 4143259612388.8 is a nuclear powered car designed for especially high speeds (up to the speed of light). It is very experimental and thus Mr. Frityy owns the only known working prototype. Rumor says that the technology for this came from the Secretiverse and that it can actually go even faster if you clock it into maximum overdrive.
Nuclengine is obviously a portmanteau of "nuclear" and "engine." HS stands for high speed.
The spedometer measures speeds in a logarithmic fashion, measuring in fractions of the speed of light. It allocates space (k/2) for space k between speed n and speed (n/10) as n approaches 0, starting with half the spedometer for the space between c (lightspeed) and (c/10).