I see what you mean and thanks for pointing those differences out.
The GTR2 model you posted is not bad for GTR2 but is much lower poly and less detail than the later model we have been working with. However it may not be a major job to use the later model as a basis and swap over the body shells.
View attachment 1185051
This is the BMW version. There are 4 versions in the GTR2 model, 2 main being the BMW and PTG with some variances in mapping between them. The different parts may be able to be changed via CSP.
Unfortunately the interior is horrendous. With GTR2 they have a separate cockpit object that is decent quality except in some cases they only include polygons for what you would see from the drivers view. To fix this is a lot of work so using the late model interior would be less painful.
The rear wing mounts lack a lot of detail as well.
I will have a look at this and see what we can do.