The Flintstones S06E10 - The Stonefinger Caper

Gazoo gives Fred a luxury car and this causes more problems, including some mysterious people trying to get a secret formula from Barney, who they think is scientist Dr. Rockenheimer. After Fred makes the mistake of telling Gazoo to get lost, the mysterious people finally knock Fred and Barney out, and are ready to kill them to get a formula Barney does not have.