In the first case you´re talking about the rx7 lm. The rx7 GT-C lm is another car that can´t be found in the mazda special lot, only won. Not too much of a difference but the rx7 gt-c lm is better.
I don´t know wich one you´re looking for. I only have the rx7 gt-c lm not the other one but anyway I can´t really give you any settings because the only thing I´ve changed in that car was the gear spacing.
Good luck