How do symbols of a car relate to the name? What do they mean? Are they meant to appeal or describe? For example, why is Peugeot's symbol a lion? Why is Renault's a diamond? Why is Opel's a lightning bolt etc. Some obvious logos are Jaguar, Porsche (family crest), Eagle, Saturn, and Dodge Ram. Some are quite interesting like Chrysler, Mercedes, Infiniti, Mercury, Chevrolet, Audi. So many to list but for most, what is their meaning?

Interesting subject

Peugeot : the lion was the symbol used by the company since 1847 (but the "company", or rather family business, is older than that; at that time they were of course not making cars). According to Wikipedia FR, it was used as symbol of quality of their blades and saws: cut speed, hardness of the teeth and flexibility of the blade.
Evolution of the logo : http://peugeot.mainspot.net/logo.shtml
So now the Peugeot cars are always linked to lions and other feline terms when they are described. Though that the front grille of current models remind me more a whale than a lion...

Citroën : André Citroën found a new gear system in Poland, he bought the rights of it and the logo reminds the shape of these gears, cf http://en.wikipedia.org/wiki/Gear#Double_helical_gears
Colors of the logo changed few times (yellow on blue before the war, more discrete later using white, and they used red background since the 80s)

I when I bought my first BMW back in 1997 at Schaeffer BMW Center; they told me that the round BMW insignia (the white and blue parts) represented a propeller. As most people know, BMW started life as a airplane engine manufacturer.

I found a good representation of the BMW logo evolution over the years.

Click to enlarge:

Renault :
The "diamond" is not their original logo. It only appeared in 1925. According to the site linked below, they chose that shape because it fitted well with the shape of the hood of their car at that time.
http://www.journaldunet.com/economie/reportage/renault/index.shtml
(click on "Suivante" link to go to the next pages to see each logo)

Neptune > indeed, white propeller on blue sky

MBSL65fan > for Porsche it is actually the Würtenberg crest, with the Stuttgart symbol in the middle of it.
Note that the same symbol is used by Ferrari ! In that case, it was the trophy of a German plane shot down in the war by a friend of Enzo Ferrari + a yellow background for the Modena city.

Audi logo is a more complicated story. Actually the current logo is the Auto Union logo, which was the merging of four makes, hence the four rings. The original Audi logo is the one shown at the top left corner of this chart, showing the logo of the Audi "family":
http://www.luxusni-auta.cz/data/mod_redaction_adv/cats/2/pic/audi_history.jpg

Alfa-Romeo : Name ALFA comes from Anonima Lombarda Fabbrica Automobili (the Romeo part was added when Nicolas Romeo took the company in 1915), founded in Milano. The crest of that city in crusade times is the red cross on white background and a dragon eating an infidel (!), also crest of the Visconti family if I understood well.
http://www.asaf.co.il/alfa/images/collect.gif

Mazda : Current logo is quite recent, and is a kind of M-shaped wings. They had another one in the 90s which was too close to Renault logo.

Mitsubishi : The name means "three diamonds", hence the logo...

Saab : Swedish Kingdom emblem

Opel : Originally a zeppelin, which became more stylized, not sure of why it become a lightning.

Subaru : Japanese name of a star cluster (Pleiades)

Volvo : commonly mistaken for a "man" sign. It is in fact sign of iron / swedish steel - the material from which the cars were made since the beginning

Great information. It seems like most logos do have a meaning. The Audi tree thing was a little strange but the rest of the symbols have a very unique story of their own. Thanks.

A whale? how?

with the big mouth:
http://www.autoblog.it/uploads/peugeot_207_uff_17.jpg
http://www.arkive.org/media/F121C21F-3EAE-4078-B188-096F830F8515/Presentation.Large/large-Whale-shark-feeding.jpg

(actually it is a commmon joke - at least on French forums - to compare these recent Peugeot to a whale, as many do not like these new front style, including me)

Not to me. It does look like it's sucking in air though.

Mercury: They used to have the Roman messenger god with the winged hat as their logo. Then sometime in the '80s, they went with a futuristic styled M (dubbed the "Flying M").

Oldsmobile: It's a rocket. Represents the old Rocket engines.

Chevrolet: Two stories about that. The first one is that the founder saw the pattern on the wallpaper of a hotel he was stying in. Second story is about how it represented the Swiss flag (Louis Chevrolet's heritage).

Never understood that logo. thanks.

I don't think they look too bad, but I like the styling of that new Peugeot 4007 suv. (Based on our Mitsubishi Outlander.)

"your" Mitsubishi Outlander? Isn't that a Japanese car? Or you just mean "the car that we have in USA"?

The car that we have in the USA.

Kia: I heard that the Kia emblem is in the same shape and size of the Ford blue oval due to Ford's previous partnership. Supposedly Ford was going to market a vehicle manufactured by Kia, but pulled out at the last minute. Since parts had already been manufactured in the shape to take the Ford logo it was too late to be changed.

Well, some Kia-made cars were sold as Ford, this was not just an abandonned project.
e.g. Ford Festiva / Kia Pride