I can't find the details of that Ferrari electric paint theory, but the basic gist was:
They had paint that when a current was passed through it the surface distorted making it rough. This paint was applied to one side of a wing that meant that when it was activated it did something (can't remember what) to the airflow which increased down force (something like making air flow slower over one of the surfaces). It was controlled by a mercury switch activated during cornering, so that when you were going straight it was off, so nice slippery wings for straight line speed. Then when you turn in the mercury moves to one side and creates a circuit that electrifies the paint activating increased down force for cornering. It was supposedly going to be tricky to master as the driver would have to make the initial turn in assuming he would get more down force than he currently had.
From what I remember this all spawned from a single picture of a Ferrari where the paint looked a bit 'dirty' or slightly opaque on the front wing.