However, as others have noted, the G70 is right on target for matching virtually every dimension of the benchmark for this model - the 3 series BMW.
However, the new 3 Series has reportedly grown
2.36 inches.
Cadillac, for the ATS, benchmarked the E90 3er - which was a mistake, as by the time the ATS was launched, BMW had already started production of the larger F30.
The most common criticism of the ATS has been its lack of rear passenger space compared to the competition; something that the 2G CTS didn't have (which, in fact, like the
Infiniti G/Q50, had more interior space than the norm for the segment).
Cadillac will replace the ATS with the new CT5 which will grow once again to around the size of the 2G CTS.
Now, maybe Genesis consciously kept the size of the G70 where it is in order to maximize the handling/performance, but as we have seen w/ the ATS (as well as the Jag XE and Alfa Giulia), the majority of luxury buyers place such attributes lower on the list (willing to sacrifice some handling/performance for more space/utility).
Part of the reason why the G80 has done as well as it has is that it offers more rear passenger space than the norm for the mid-size segment (and hence, adding to the value quotient); have concerns that in not doing so will hamper sales of the G70 somewhat in the US market.
But at the same time, probably is a good thing that Genesis didn't simply offer a 4-door version of the
Stinger (there's more differentiation btwn the 2 models), but an inch or so more rear leg room would make a difference.
Going back to the whole G70 having a nicer interior and more amenities than the G80, that's pretty much unavoidable w/ regard to timing.
For instance, many think the Civic is better than the Acura ILX as it sits on a more modern platform and offer tech that the ILX doesn't; it'll change when Acura redoes the ILX.