Test Drive 4 does not allow the game to run without the CD-ROM when attempting to start a race, even if you mount the disc image in a virtual drive.
This archive comes with the official v1.2 patch by Accolade which adds the Pontiac GTO, and pre-patched 2.EXE, TD4_3DFX.EXE executables.
It’s recommended that you first patch a fresh installation of Test Drive 4, then replace the modified EXEs.