Sorry, but I don't recall that line ever being stated in a Charlie Chan movie. One or two other famous detectives were refered to during the series (I'm thinking of two "Bulldog Drummond" references in the film "Charlie Chan in Rio"), but I don't believe the great Mr. Moto was ever mentioned.
One film, "Charlie Chan at the Ringside" was halted during early stages of production due to Warner Oland's breakdown. This movie was retooled as a Mr. Moto picture and retitled "Mr. Moto's Gamble." It is pretty certain that the phrase you mentioned was stated at least once in this one!
Never heard that line in a Chan film....Can tell you
that HelloMoto.com Is the website for motorola cell
phones though!!! I know.. I know Unrelated,But I could'nt resist...LOL!!