I could make a list with 100 cars that need to be added but here some important ones.
Many cars from finnish, estonian, czech championship would be great (Like the ones listed above or that i link).
Many have some bigger history. Here is a small list i made.
F2 (Rest the missing 24 cars like Clio Maxi,xsara)
S1600 (clio, c2, punto, corsa...)
Chrysler Sunbeam Lotus group 2
Skoda 130 RS Group 2
Datsun Violet 710 Group 2
Saab 96 V4 group 2
BMW 2002 Ti group 2
Trabant P601 group 2
Volvo 142S group 2