Mercury. It's smaller and looks sleeker.

Thanks to both of you... fascinating and I'm rarely flummoxed.

Speaking of 1958, yesterday I learned there was a French market DeSoto; front clip DeSoto, rear clip Plymouth. This was news to me.  

Tough choice but DeSoto.

I've read the former, and will look for the latter  

What Jack said.

Cute!

The 1948 has presence and is handsome. The 1949 is plain. 1948 wins for me.

Plymouth for me too.

Ford. I like its proportions and headlights.

Although I also prefer the 1951 grille, the Ford wins.

@kevins Indeed it is.

Pontiac for me. Love the side spear.

Ford. Love the stacked headlights.

Mercury by a mile. It looks sleek, the Pontiac doesn't.