From 1st post
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7. Click Pack -> Add File to Archive, in the new window press the ... button to the right of the text box. Browse to where you extracted ChrRaces.dbc, select it and press open. The text box should have filled in with "ChrRaces.dbc", now replace it with
DBFilesClient\ChrRaces.dbc
and click ok.
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I think it was there, and you just skipped it.
Edit: If it doesn't work properly, make sure your other MPQ's are not loading another ChrRaces.dbc overtop of this one.... that just makes it ignore this one. If you use Kynox's MEF, put this MPQ on the last line of the config file, or rename the MPQ to something at the end of the alphabet like "patch-z.MPQ"