Actually the chances that you'll have a problem are very low, probably 1/10 at the highest, but there is a chance and it's so easy to run them separate that it's better to just avoid any chance of problems and run them separately from the beginning.
mine are ran together and I do not have a problem, both down the driver side. However when I rewire everything and get something bigger then 8ga wire, I will run the power wire down the other side.
My old car did have a little whine ran together, however you could only hear it if the head unit was on and the volume was ALL the way down.
__________________ SE-R SpecV
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. - Ben Franklin
Mine whines on the radio only for some reason. But then again I didn't wire my car. It was already done, and I haven't gotten around to doing it again.
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1987 300ZX Turbo, 5 Speed, TurboXS H-34 BOV, WAI, Under Construction
Clutch, Wheels, Tint, Paint, Interior, HID
yes, running them down the oppoiste sides of the panels is more then enough.
__________________ SE-R SpecV
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. - Ben Franklin