In gt7 we have.
787B 1991
R92CP 1992
962 C 1988
Sauber C9 1989
XJR-9 1988
Is that all of them or are there some missing?
Those are some, if not, the most significant.
You have the 3.5 liter beasts (shame those regulations were used to kill Group C, but they still produced some of the most magnificent cars ever) like the Jaguar XJR-14 which won the WSCC in 1991.
You have the Peugeot 905 Evo B that dominated the WSCC in 1992 and won both the 1992 and 1993 24hr of Le Mans, the last of the Gr.C winners. This 905 was featured in GT4.
And then you have the 905 rival, pretty much it's only rival during 1992 and 1993, in the Toyota TS010 which placed 2nd in Le Mans 1992. The prototype of this Toyota had so much downforce that it broke ribs of 2 drivers trying to reach the "limit" of that car.
Other less significant cars, but still nice to haves, and to add more of them Gr.C cars to other manufacturers, would be the Lancia LC2, the Aston Martin AMR1 and the Ford C100, which are some of the first years Gr.C cars. Of the early years, the most dominant car was the Porsche 956, but that is almost literally the same car as the 962 so it really wouldn't amount too much in adding it.
And after Gr.C, one of the most appealing eras to fans of motorsport were the LM GT1 cars. Of which we already have the Mercedes CLK-LM and the McLaren F1 GTR LongTail.
However, we are still missing a few cars of this era, that have a lot of fanbase, and are significant on their own right, and some have even been part of Gran Turismos in the past (started in GT3 and GT4) like:
Toyota GT-One TS020. This one I'm still incredibly surprised at how it's still not in the game given the following: A very famous japanese race car designed just to win Le Mans and almost had it in 1998 (had a puncture while chasing the leading BMW V12 LMR), a Toyota, a Gran Turismo icon, probably an even bigger icon of the game than the Suzuki Escudo.
Nissan R390 GT1
Panoz GTR-1
And the 1998 Le Mans winner, Porsche 911 GT1. We have a 911 GT1 in the game but it's the road version and from 1997. The 1998 is quite a bit different and... it's the race car that won Le Mans, the only GT1 car to win Le Mans in fact.
Among the Gr.1, GT7 is well stacked in the LMP1 class.
But a few missings from this group (Gr.1, not LMP1) are still notable by us such as:
Bentley Speed 8 (featured in GT4 and won Le Mans in 2003)
Any of the 2000s Audis, either the R8, the R10 TDi or the record breaking distance covered in Le Mans R15 TDi. The first two (R8 and R10) have featured in past Gran Turismos, with the R10 being a premium car in GT5/GT6.
Toyota TS040, which won the WEC championship against Porsche and Audi.
Everyone had all of the invites for a month in April 2022 - which is less than a year ago and, as we know, GT7 isn't even a year old yet...
We all know why... But I actually understand his statement. Excluding the glitch party we had and also PD's goodwill to offer us invites for 1 month, I personally have never gotten a Ferrari Invite from the roulette. Ever...
Now if he bought the game in May or after... Yeah, I can totally see people, even to this day, not even having gained an Invite for some manufacturer. Unless PD's offer actually extended to even the people who bought the game after that (confirmation needed).
If he bought the game at launch then he's wrong of course.