Did I use the word "redundant" correctly, while describing a truck
bed?  While walking through a parking lot with my wife recently, the
subject of very large trucks and SUV's came up.  I stated "A lot of
trucks seem to have truck beds that are redundant".  My wife said that
you cannot use the word redundant to describe a truck.  I believe that
you can use this adjective to describe anything that exceeds what is
necessary or normal, as descibed by the definition in Webster's
Dictionary.

Thanks for you help.

I believe that "redundant" in this sense means exceeding in numbers,
not exceeding in size.  For example: "The four additional trucks were
redundant; we needed only one truck to carry the payload."

However, the dictionary definitions I've seen are ambiguous on this
point.  Perhaps someone can find a usage note that is more clear.

Although it is not the word I would have chosen, I see nothing
incorrect in your use of the word "redundant." One of its many
meanings is "characterized by or containing an excess." In this case,
I presume you were referring to an excess of cargo space.

From Merriam-Webster's Unabridged Dictionary:

"redundant...

1 a : exceeding what is necessary or normal : SUPERFLUOUS, SURPLUS
<older areas, plants and occupations are becoming redundant and
obsolete> Solomon Barkin>...

b : characterized by or containing an excess <the skin was redundant
and lay too loosely on her fingers> Jean Stafford..."

Since "redundant" can also mean an excess of quantity, as pointed out
by justaskscott, I think I would have used the word "overlarge," but
the English language offers a lot of leeway. Indeed, it might be said
that there's room enough to drive a truck through. ;-)

I would dare to differ, mrahfaldt-ga.  
In the situation you describe, one cannot know if the truck beds are
redundant.  They may be super large so that you or I couldn't imagine
why or how they could be useful, but they could be, and probably are,
otherwise they wouldn't exist.
Ditto for the number of trucks.
Redundance implies a surplus that could be used, often a backup
factor: having more trucks in case some are out of service;  or
redundancy in systems: duplication as a safety factor (processing
capacity and data storage), or redundancy of controls, say, in
financial transactions.

(I don't like Jean Stafford's usage:  superfluous and redundant are
not always interchangeable.  Says me :)

myoarin,

Please note that I did not select the Jean Stafford quote: the editors
at Merriam-Webster did.

In issues related to the English language, Merriam-Webster's
Unabridged Dictionary is a reference source of considerable repute.
Are you? ;-)

Pinkfreud,
I knew I was taking on the big guns by posting after you and
Justaskscott  - and the big Merriam-Webster's.
I will fire back with amo from Webster's Encyclopedic Unabridged
Dictionary of the English Language, "... entries are based on ... The
Random House Dictionary ...".
(If necessary, we can weigh each and see which one is the heftier authority.(: )

Redundancy:
1 the state of being redundant
2 superfluous repetition or overlapping, esp. of words.
3 a redundant thing, part or amount; superfluity.

Redundant:
1 (I plead 5th amendment, it's about language)
2 being in excess, exceeding what is usual or natural; a redundant part,
3 having some unusual or extra part or feature
4 characterized by superabundance or superfluity; lush, redundant vegetation
5 engineering ...

"I stated 'A lot of trucks seem to have truck beds that are redundant.'"

A truck bed is an integral part of a truck; it cannot be "redundant" 
- too large for any load, maybe, but it has to be there.  Something
that is redundant  can be removed without impinging on the function of
the object under discussion.

Scott pursued this line, and you also did, by suggesting that the
quotation referred to cargo space  - which may have been what
Mrahfaldt was meaning, but he said something else.

As to M-W's quotation:  "the skin was redundant ...", I see this as a
similar misusage.  The skin  - like the truck bed -  cannot be
redundant.  Perhaps: "that part or portion of skin that could be
removed was redundant," although I would avoid this usage, and I doubt
that Jean Stafford was discussing the possibility.

Maybe I could have left out much of the above and just said that,
since you were only defending M-W, and we all pretty much agreed that
we would not have used "redundant" in the quotation.

Does that make me "a reference source of considerable repute"?
I doubt it, but I'm weightier than both dictionaries ...  ;-D

My initial thought was "is he talking about bed liners?" Which would
be an extra, un-needed, layering of support on the bed. But it didn't
seem that way. But, double checking the etymology we get

Etymology: Latin redundant-, redundans, present participle of redundare to overflow

So, I suppose, say on a dualie, where the bed does seem to overflow,
it could be a very poetic description.

I think that mrahfaldt-ga is speaking to the point that it would not be
surprising to learn that a majority of people never use their truck bed
for any real purpose at all.

In other words, they have all sorts of cubic feet of cargo space that is
never or rarely used, but rather transport their loads, such as groceries, 
n the cab of the truck.  This is probably more so, considering that most
newer/larger trucks have larger cabs with backseats, etc.

By pinkfreud's excerpt from the Merriam-Webster's Unabridged Dictionary,
"... exceeding what is necessary ... SUPERFLUOUS" indeed, it appears one
could say that the beds on probably a large percentage of trucks could
be considered redundant, that is, trucks have more cargo space than what
is needed, not that the truck beds themselves are too large.

Bottom line that is that perhaps lots of people should trade their trucks
wherein cargo space is wasted, for another vehicle, an SUV for example,
wherein other cargo space would be wasted.  Forbid that people get sensible
and get smaller, more efficient vehicles with little wasted space.

Looking Forward, denco-ga - Google Answers Researcher

A lot of english words have uses that are not wrong, but still really
bad.  This is one of those uses.

Calling the whole truck redundant could easily be taken to mean that
the whole truck is not needed in addition to some other object.  Using
words in ways that have multiple meanings should be avoided,
particularly if your intended meaning (a redundant object simply being
too large) is less common than another meaning (a redundant object
that performs the same function of another object, or a redundant
group of objects that perform the same function).  I would guess that
people would be less likely to confuse your statement if you said
"excessive," even if they could sometimes mean the same thing.

If I heard you call a truck bed redundant, I would probably respond by
saying "yes, one would have been plenty" to mock you and express my
disapproval of your word choice.