Auto cables? I think you mean audio cables, right?
Well, back in the day...
... before video became so prevelant, audio interconects were anywhere between 50 to 110 ohms or so. Audio didn't care. IT worked quite well with either. It still does.
When video came into play, the matter of 75 ohms became more of an issue. Many manufactureres would set up another run to use the same production machinery with a different impedance cable and simply put yellow RCA connector on the end and charge a few bucks more.
As time went on, savvy manufacturers realized that 75 ohm cable doesn't really cost any more than the 50 - 110 ohm audio cables, and, since the 75 ohm stuff works well with audio, why not simply make ALL cables out of 75 ohm stock. All they need do is put on yellow connectors. They already put on red and white ones. What will adding another color cost?
Now, it's rumored that 75 ohm cable labelled "digital" has a wider bandwidth, but I'm doing quite well with a standard 75 ohm "composite video" cable for my DVD/receiver digital interconnect.
Of course, they might still charge a little more for an "official" video or digital cable but what's the big deal? A guy's gotta make a living, don't they?
My take? If an audio cable works for your video, go for it. Conversley, why would you want to spend more on a cable labelled "digital" for an audio signal?
