It will depend on the changer you have if you can mount it vertically, most changers you can. Just check the owners/installation manual, there will probably also be a set screw to change according to a horizontal or vertical install. As for placement, put it where ever you like, just check under the car before you drill and use screws 1/2" or shorter. If you can I would suggest running the changer cable on the opposite side of the power wire, however if this is a problem I doubt you will get an alternator wine from it. I have never gotten an alternator wine from a changer cable before, they usually have allot of insulation and shielding. Now speaker wires that is another story, they need to be at least six inches from a power wire, and if they cross, cross at a 90 degree angle to reduce the chance of noise.
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