All the BMW M3s in the game, complete with stats:
M3 '04 - 466PP, 344BHP, 1570KG
M3 CSL '03 - 490PP, 361BHP, 1385KG
M3 Coupe '07 - 488PP, 422BHP, 1655KG
M3 Coupe Chrome Line - ???PP, 475BHP, 1625KG
M3 GTR '03 - 489PP, 382HP, 1350KG
M3 GTR Race Car '01 - 568PP, 452BHP, 1120KG
And if you want to extend GT5's M Car range -
M Coupe '98 - 449PP, 322BHP, 1465KG
M5 '05 - 517PP, 509BHP, 1715KG
M5 '08 - 513PP, 509BHP, 1855KG
Z4 M Coupe '08 - 469PP, 347BHP, 1495KG