Look in %LOCALAPPDATA%\CrewChiefV4\sounds\driver_names (usually c:\Users\ "username" \AppData\Local\CrewChiefV4\sounds\driver_names)
for some likely sources for the sounds you need.
Drag them into Audacity.
Use the mouse to select a section of the file and press Play to hear it.
When you have a sound selected delete the rest.
Select another sound from another file then Ctrl/C to copy it and Ctrl/P to paste it into your new name.
Repeat as necessary.
When you're happy with the result Export it as a mono MP3 file with a .wav extension.
It's made much easier because mr_belowski did a great job of keeping his voice the same as he recorded the thousands of names, this means you can chop bits from various files, stick them together and the result sounds smooth and natural. No need for clever audio techniques for changing the volume, pitch, pace etc. (though Audacity offers those).
Advanced users might use other Crew Chief sound files, in
I'll add these steps (the forum isn't allowing me to edit my post ):
7a. Copy the file to menu File/Open voice files folder driver_names (%LOCALAPPDATA%/CrewChiefV4/sounds/driver_names)
7b. Restart CC then click My name: and select the new name
7c. Does it sound right in CC?
A more tricky than usual example: I stitched together bits from SUmma.wav, BEE.wav, brEEN.wav, SCHMITS.wav and bit_KURVE.wav then added silences and deleted some bits that were too long. 10 minutes later I have this