Bruce, I think you might be downplaying the meaning behind a name too much.
An automatic transmission is named such because of its overall functionality. But over time it has become associated with certain features, namely a torque converter. There have been derivatives of the aforementioned transmission, but they were only modifications. (ie. Steptronic, Tiptronic transmissions in BMW and Porsche) They were mechanically the same however.
Now when you talk about the M-DCT or the Audi/VW DSG. You are talking about a system that is mechanically different. No torque converter transmission with a gimmick shift lever, but an actual clutch. So the only trait that is shared between the 2 is that they both use gears, and that they both don't require the user to work a manual clutch. They are similar in direct interface alone which would be a pretty stereotypical way of associating anything. In this case, a new name is warranted because the DCT is not an automatic transmission. It simply just functions 'automatically'. The difference is that the same word can be used to either describe or name the product in question. Yes, it does function automatically for the user. But it is not an "automatic" transmission. A description that many consider to be taboo when used in conjunction with a competetive sportscar. While you may be sitting there wondering why it matters what name you call it by, we are sitting here equally baffled and wondering why you won't just call it what it's named. Stop trying so hard to be different!
Lastly, you said you wife was a car enthusiast but she knew nothing about cars. I believe you use the term enthusiast incorrectly here. I think the term shouldn't be used for someone whose interest in cars is only skin deep. I'm not trying to bash your wife or anything, and there is nothing wrong with just liking how cars look and not caring much more about them. I'm just saying that she wouldn't typically be classified as an enthusiast or a fanatic.
In both my cases above, the word doesn't matter quite as much. Just an arbitrary collection of letters. The meaning behind the word however is important. The meaning is what carries the weight and the idea with it. So, if you don't use the correctly matched words with their significantly more important meanings then you've just got something that poeple don't understand and will argue about.