Relay: A device in which a set of contacts is opened or closed by a mechanical force supplied by turning on current in an electromagnet. The contacts are isolated from the electromagnet. It's purpose is to use low current to control a high current circuit. In other words, it uses current to move current.
Solenoid: An electromagnetic device that uses movement of a plunger to exert a pulling or holding force. In other words, it uses current to apply force.
A Relay is in the middle of a circuit, whereas a solenoid is at the end of a circuit.
The doohickey on the strut tower is a relay. The doohickey on the starter is a solenoid.
Take care,
~Chris
PS- Christine was a 58 Fury in the movie, too.