From the top of my head:
- GT an GTN 2003 from RSS,
- WTCR 2018 from Maki and Delpinsky or from tommy78 (very good mod pack),
- BTCC 2018, 2019 from Shaun Clarke
- WTCC 2017 from Ptsims,
- WTCC 2007 from Ciraceonline,
- wec, gte, gtlm 2018, 2019 from URD,
- alms DPi 2014 from IER,
- LeMans 2003 from VRC,
- DRM,
- WTCC 1987
- GT1 1997 from URD and Legion,
- TC legends from Bazza,
- prototype Legends from Bazza
- TransAm legends by Bazza and additionally Uncle M
- V8 stockcar Brasil
- V8 Australia all season 2015-2020 and 2011
- Petrobras Marcas 2018
- TC Carretera 2016
- TC2000 2017 from ACFL
- indycar 1998, 2012,2018,2020
- nascar 2018,2019
- formula 2,3,...
Surely forgot quite a few. We are also in the process of getting quite a few almost complete fields of ATCC 80s seasons and also DTM 1991. And if you do some BOPing, you can mash together over 20 other championships with at least 90% accurate liveries and cars and at least 1 driveable cars (GTO, several BTCC 90s, several DTM 90s, GT1 early 90s and mid 00s, Alms 2006 - 2013,...), and s***load of single make cup car championships.