msd boxes and other ignition boxes will always work better if mounted in the car. under the hood they are known to go bad. they will see too much heat, water, etc. cop's are definately not needed and are a waste of money. alot of people buy them because they think they look cool, and it is actually a downgrade from your stock coils. get yourself a good set of plug wires and a msd box and you will have no spark issues up to 800 hp.