Corrected entry: The homing device Bond puts in the inside trunk lid of Goldfinger's Rolls is magnetic as shown when Q is demonstrating it. However, like the other body work, the trunk lid of that car would have been made of gold, to which a magnet will not stick.
William Lanigan
20th Oct 2011
Correction: The entire car is not made of gold, just the body panels. Since gold is very heavy but bends fairly easily, any gold on the car would have to have some kind of support structure not made of gold. Bond would have attached the homing device to this support.
Guy