am trying to say:

Ford sells more Fords it not because they are Fords, aka it is not because consumers regard the Ford brand provides them some certain additional value, It is just because it is there, it is within their budget and it has some certain functions that fulfills their needs. The same consumer will go to GM or Hyundai or Nissan as long as their cars offer the same features - hence the brand loyalty is low and hence the the value of brand is not there. Same goes to Lincoln - it is the same Lincoln JFK rode in 40 years ago, unless you throw in an air suspension or GPS, not a lot of people hesitate to switch to a Cadillac or MB.

Volvo, Lexus, MB or BMW are quite different. Consumers go to them already with some certain perceptions of the cars. You buy Volvo most likely thinking they are the safest car (not true) and it makes you look smart b/c your college professor had one; You buy a Lexus thinking it will drive for 200K miles without even have to go back to service, you buy MB thinking it is the crown jewel of German engineering; You buy BMW thinking it will drive up to 300mph in 3rd gear....those are perceptions that consumers have and they worth a lot of money. If you re-brand a new BMW car as WMB, they will not sell, versus Lincoln or Ford, if you re-brand them as Hoover or Henry, you probably sell the them the same amount - I personally thinks you will send more!! Because lots of these American brands to Americans means "oh boy, Dodge, never again".

Other than serving the American's the nostalgic sentiment and patriotism - which, I guess, is also somewhat valid reason,  I don't think this makes a lot of sense.