I'm not sure who was saying that it had been tried and it didn't work
as several people of given examples of successful racing aircraft
using surface radiators.

Several famous Thompson Trophy (sea/float planes) winners used surface
radiators to some degree. Most notably the Supermarines. Don't know what kind
of problems they had, but its worth a look, and a grain of salt.

The guy that was saying an airplane waiting in line is the same as a
car idling in traffic is off base because even with zero airspeed that
prop is blowing turbulent air across the cowl.

The wing radiators aren't going to be as efficient per unit area as
the cowl or other parts of the aircraft in turbulent flow.

I was under the impression that Voyager used fuel efficient versions
of the traditional aircooled engines commonly used today, so I'd like
to hear more about the pickup truck stories.

And just because something has been tried before and failed, doesn't
mean the concept should be abandoned. Haven't you ever seen anyone
flub an attempt or do an experiment with an agenda? Why should their
oversight stop others from doing better. And those old times were
lacking many of the tools available today, mainly the cheap
availability of computing power. You have part time hacks doing
analysis orders of magnitude more accurate than they were doing back
the 20-30's.