Why are the ignition Plugs Cables so pricy for both the 348 and the 355 compared to said "Merc" or "BMW" Is it because of the Connectors on both ends? Is it because of the "special" Cable marked MERU? or Is it just because it's Ferrari? BTW, how do you test if the plug cables are good? With an Ohm meter? if Yes, what should be the reading?