There isn't a single definitive answer to "fastest car in the US" because speed records are often context-dependent (track vs. public road, modifications allowed, etc.) and constantly challenged. Furthermore, privately owned cars may hold records that aren't publicly reported.
To find the fastest car in a specific category (e.g., production car on a specific track), you would need to specify those parameters and consult relevant speed records from organizations like the National Hot Rod Association (NHRA) or Guinness World Records.
