Download Car @: Renault_5_GT_Turbo_Cup_v0.6_updated_by_Assettoland_2in1_for_AC_v1.9.7

The <INSTALLATION_FOLDER> usually is located in:
C:\Program(x86)\Steam\steamapps\assettocorsa\

You can find your Track-Directory in:
<INSTALLATION_FOLDER>\content\tracks\ <---

The track directory of the new track should reside here.