Having several competitive cars is what keeps a class healthy... you see the same thing in ITA. Off the top of my head you could have any of these below on the podium:

Integra (2 generations over 10 years)
CRX
240SX
Neon (SOHC or DOHC)
Miata (2 engine choices over 7 years)
325E
Sentra
NX2000
Civic (3 generations over 12 years)
Saturn
MR-2

Christian