The top pic is a Mercury.
That ’48 Buick Streamliner is gorgeous in a kind of cartoony way, but it looks terribly impractical. Shit, the thing must be 20 feet long and it has a tiny cockpit that two people can barely squeeze into.
I prefer the less exaggerated proportions of Harley Earl's Buick Y-Job of ten years earlier:

And the 1956 Buick Centurion is kind of cool:
