Hinda made the nsx at one point, nissan had their skyline, toyota the supra.
What's left of any of that? right...
Rebadged cars are nothing new but it has become pervasive. Most vans down here are built by either fiat or peugeot. Mercedes, which used to reign the diesel market with their indestructible 4, 5, and 6 cylinders (om617 anyone?) now has renault diesel engines in some vehicles because: environment. Developing an engine yourself these days is almost not worth it. It was the last straw to compete in a market I guess. If you can't afford to build your own mid segment car, just buy one and put on some different fenders, bonnet and headlights. It's been done since the 90's at least. Not sure if you got the rovers in oz back then but the rover 600 was a honda accord in drag for example. When rover went belly up those cars became dirt cheap and I made good use of that :) but I digress.
Let us hope that some brands will survive or combine.
Cheers,
-P

