There seem to be two standards for car stereo spaces (in addition to the nonstandard sizes so common for factory stereos these days): the one used by East Asian car manufacturers and the ones used by the rest of the world.
The rest-of-the-world size is the size of the empeg's sled. It also matches the sleeve with which most big-name aftermarket stereos come that usually clamps onto the dash with those bending clips. This is sometimes known as Euro-DIN.
The Japanese size matches the size of big-name aftermarket stereos without the sleeve. These stereos are usually screwed into a frame that then bolts into the dashsomewhere.
There's apparently also another one, J-DIN, that's a little bit wider than ISO-DIN, but otherwise the same.
This means that it's difficult to get the empeg in East Asian cars, because their slots are too small. The empeg would likely fit in there without the sled, but that's not really an option.
Anyway, which of these standards is actually DIN I don't know. It's possible that they're both specified. But unless someone wants to purchase the specification, I doubt we'll ever know. And it's not really useful knowledge anyway.
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