I don't know about Gm designing things.
they like most design to be adequate not perfect.
C3 `s have a lot of problems in the stock steering.
Yeah, a lot of US muscle cars seemed to only be able to perform well in a straight line; the 'vettes were always a bit better I thought with the IRS and such.
If you're doing a redesign of the geometry, correcting bump steer, centre of gravity, centre of roll, etc. you may do a better job. If you're just swapping over to the other side, using components from other cars that are a close fit, this is where you can run into trouble, trying to clear components and such.
I agree about adequacy; trying to squeeze what you can out of the budget; you can only dedicate so much to design, with the manufacturing processes of the time, etc.
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