You are undoubtedly right. However, it is my understanding, from what was reported from St.Tropez, that the MMC has again invested to make the Aero US crash compatible for next year. Was there mention when the new round of crash tests will begin?
The prototype already had the petrol tank in the new position, and I understand that the tank in the trad will also be moved into this central position; as well. No details were given of the exact state of the testing regime, as the work on the Series IV is an ongoing project.
I do not believe that was ever correct of Morgans until the last few years. All US Morgan trads sold in the US in the last 2-3 years are selling at a premium. Those older than that sell for a much higher premium.
I think that the UK and North American markets have operated to a different dynamic for some considerable time, as my first Plus 8 was sold at a profit after nearly four year of ownership, my second, after a shorter period I basically broke even, but my third was sold at a loss in the early 90's.

Whilst Peter Morgan was very canny at balancing the price versus quantity equation for very many years, once they started to increase the production the writing was on the wall for profit-taking in the UK on Morgan's with one or two exceptions. Harvey-Jones has a lot to answer for.
However, the Aeros seem to be vulnerable for other reasons. I haven't convinced myself what the reasons are yet but this forum has been very helpful.
Whilst Aero residuals have changed as the perception of the cars has changed, I don't think that the current residuals (again in the UK) are any worse than other Morgan's, or for the Roadster in particular the Aero's may even be stronger.
I doubt very much whether anyone in the UK buying a new Morgan expects it to be worth more than they paid for it in a few years time, as these days Morgan's depreciate until they reach sort sort of threshold and then they do not normally drop much below that. For Series I Aero's this seems to be a main dealer price of circa £35k, although you occasionally see private cars being sold off for whatever reason; for much lower prices.
There is little doubt that the Aero 8 has not been the success in the USA that many of us would have liked to see, and there are many reasons for this. Maybe the automatic gearbox will do the trick, but I do not know enough about that market to say whether this single item will be the complete panacea; on its own I quite frankly doubt it.