The B13 SE-R and NX2000 will be lumped in the "Civic" class. The B14 and B15 may not be allowed in any ST class at National level events, unless they correct their omission (the letter I wrote hasn't been reviewed, yet).
http://www.sr20-forum.com/autocross-rallycross/50830-write-letters-b14-b15-scca-solo-st-classification.html.
This structure for "STC" was sent to the SCCA board for approval, which usually rubber-stamps any recommendation from the Solo Events Board.
Street Touring Compact (STC)
Acura Integra (1986-2001)
Audi A4 1.8T
Audi TT Coupe and Roadster (non-quattro)
Dodge/Chrysler Neon
Ford Escort GT (1991-1996)
Ford ZX2 (1998-2003)
Honda Civic (1984-2000)
Mazda 323 GT & GTX
Mazda Protégé (1999-2003, NOC)
Mazda Protégé MP3
Nissan 240SX
Nissan NX2000 (1991-1994)
Saturn SL, SW, SC
Sentra SE-R (1991-1994)
Subaru Impreza 2.5 RS (1998-2001)
Toyota Celica (1986-2005, non-turbo)
Toyota Corolla FX16
Toyota Corolla (1984-1987)
Toyota Corolla (1988-1991)
Volkswagon Golf, Jetta, Passat & Beetle (1.8T & TDI)
Volvo S40 (non-T5) & V40
Sedans & coupes (4-seat minimum, non-sports car based) up to 3.1L normally aspirated, NOC