I don’t know FCE, but if you drop a 24p clip into a 30p sequence in FCP, it won’t play properly. Canon is about to release an EOS plugin for FCP that will allow easy transfer of DSLR files into FCP.
You didn’t mention if the camera was panning to follow the car, but if it was, there are definite speed limits for panning in 24p beyond which the image will stutter. If you look in a copy of the American Cinematographer Manual, there are charts/graphs that show you the proper pan speed for a given frame rate. If you exceed it the image will stutter.
John
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