Perhaps they don’t call themselves biological or mechanical. Those are human terms, they may have different ones.
Exactly - even better.
They probably don’t call themselves either of those because if you are trying to compare it to us humans think of it this way: we don’t go around saying “I’m a biological organism”. We just say “I’m a human” or “I’m a person”. But these are the types of unanswered questions we will always have, I guess it’s just a matter of opinion.
It’s only a matter of opinion to us. But, for all we know if they read anything on this site about us talking about them, they may think we’re nuts.
That would be like us reading stuff that aliens wrote about us! 
WEIRD!!!
I wonder if that’s the case somewhere out there. 
Could be. We have found a faraway, habitable planet. find some new organisms and such. But if you would really like to know what they would call theirselves in their world, it would be:
CARS!!!
It’s not a different planet, it’s a parallel universe. They still call it Earth.
I always thought of them as Terminators, but in reverse. So they’re surrounded by metal exoskeletons, encasing living tissue. 
We know from the recent Cars 2 TV spot that they… urinate and defecate. So they almost certainly have digestive systems.
Do they slaughter and eat tractors? Or combine harvesters or bull-dozers (from Mater the Matador), for that matter? Would Beetles be exotic food in China or South America?
Presumably they have lungs because they breathe, sigh, and pant. And talk, so that includes vocal cords.
Eyes… yup. Do they have ears? Are they around their side windows? How do they wear glasses?
Telescopic utility arms for hands. Tires for feet, with rubber as their ‘shoes’. As someone here pointed out, flexible facial muscles to pull expressions.
It’s fun (and frustrating) to ponder over these rules.
I call them mecha-biological because they’re biological first and mechanical second. It seems more respectful to fulfill the entire biological word other than shortening it, since it’s more in depth for these car’s special features as well.
Also, rims can also count as their shoes too, since you notice that Lightning McQueen had gotten some new rims during his help with the town.
@thedrivein Yes, they can wear glasses (Mater’s Tall Tales). As for the ears, I wonder that too. What I really wonder though is how they construct many of the things in their world?
There’s a part of a car that’s already called a shoe though. That’s why I never really counted their tires as shoes. For some items, like to push or sometimes pull in, they use their tires as if it were their hands.
I think they do eat tractors and combines. As for the exotic food, yeah I agree, I think they do that also. They don’t have ears, but I always thought this: Inside of the the window, all you see is gray. When they use headphones, the sound waves hit the window and then go through to bounce off of what that gray may be. That, or around the window is a bunch of sensors or holes that allow them to pick up sound.
As for glasses, in Unidentified Flying Mater, we’re able to see how they wear glasses. They just, well, do.
They have blood though; I learned that recently. 
In Monster Truck Mater, Frankenwagon’s monster’s head has a huge cut that has dried up blood all over it. Also, on the wrestling ring floor there are tire tracks, oil spills, and some red blood marks.
My head hurts. 
Cool. I can understand about the blood. I totally believe that they are made of similar stuff on the inside as us. That’s how I think of it. 
The blood means they have hearts. Aww…<3
By the way, I fell for your icon. 
you’d think blood equals transmission fluid, but, maybe they were punching some kool-aid pouches during the match! 
Also, the ear thing, maybe they have audio recievers inside their car? Like a replacement for the radio?
And, if someone was to go inside the car, would it count as a transplant? or even, rape?
It could be, can transmission fluid be red? 
Yeah I think they may have something picking up the sound waves. I mean, they much, or else they couldn’t hear!
I don’t know if opening their doors is rape. To define what would be rape to them, we would have to know how they reproduce I guess. But I totally get what you mean. Like violating them in some sort of way.
Maybe doors are there for surgery?
Actually, can Cars even open their doors? I’m not sure but I can imagine it might be akin to a human partially dislocating their arm. And can they be driven?
It’s possible, but no one ever really saw it happen.
They’re aware that those are doors though.
“Ohhh! I’ll never wash this door again!”
Love this comment. Both parts. Yeah I think it is probably some kind of a radio that they hear with since not all cars have antenas (sp?) to pick up radio frequency it is totally possible that it is just an internal kind of thing.
so, in regard to doors opening to their insides, their insides are made up of cotton, seats and pretty buttons?
And, the trunk? What about that? maybe THAT’s where they get their boogey on…