Family cars growing up:
Gerta (a Volvo - she was Swedish, you see)
The Squash (an orange/ yellow Dodge Colt)
Barbara (a first generation talking Datsun Maxima - my father thought the voice sounded like my dead Aunt Barbara)
My cars:
Ozzie (Mazda)
Monstro (a giant gray Chevy Caprice)
Midori (green Toyota pickup - Midori is green in Japanese)
Nameless (ubiquitous black Honda Civic)
I used to drive a Yugo that I named Victor (looked much like this one). Never once got even a chuckle- sigh. (Downside of working in a state with bad schools I suppose.
I drove a Monte Carlo when I was a teenager that I called Jean (from the “moved like Harlow in Monte Carlo” line of the glurgetastic song Never Been to Me).
My '79 Monte Carlo’s name is Monty. 
Our family’s first car (now mine), a '93 light blue volvo station wagon nee Thomas/Tommy the Tank Engine
Upon purchase of our second car, a '99 dark blue volvo station wagon, Tommy was renamed Blue Steel, and the new car, was, of course, Magnum.
Naming cars and other (more or less) inanimate objects is a tradition in my family. My late aunt started it off (to my knowledge) by naming her 1957 Plymouth Lily Belle. When she traded it in for a '67 Buick, the new one was named Ork Nork for some reason. I know she never liked that car.
So, my first car, a multi-colored 1957 Volkswagen bug, was named Pipco, because it most helpfully had the word lettered on the engine lid. My next VW bug was Kitty because . . . forget it. Too weird.
Next, the Fiat 124 Spyder, was Red Bastard. If you’ve ever owned a cheap Italian car, you know why. Then there was my Rabbit GTI, which my mother named Snickelfritz. The Acura Legend was ChOBaQ (“success” in Klingon) and my current ride, an Audi A4 is Zsigmund, Zsiggy for short.
Oliver 
My S10 truck is called “Twuck” because it’s a baby truck.
My Blazer is called Big Red because, well, it’s big and red.
The Mustang is called 'Stang because I’m not creative. 
My parents’ Dodge Dart was The JuneBug.
The Gremlin has become “my GremChild,” although it’s long since gone to that Great Scrapyard in the sky. Ditto the Pinto that was nicknamed “the Death Trap” not because of the rear-end collision thing but because the engine was only mounted on the block by one bolt.
My Escort was “the Grey Bitch.”
My current car is “Baby.”
my three year old beige ford truck is “old blue”
my new black ford truck is “Lucille”
in high school i had a '77 suburban “the hearse”
My wife and I called the '94 Dodge Dakota we had (I totalled it a couple years ago) Wienertruck. We bought it in 2001 to drive/haul our stuff from NJ to IN for grad school and we were extremely worried that it was a beater – previous owner used it for their landscaping business. There was a radio commercial at the time for a charity event which said something like “Fun for everyone! Just show up – everyone’s a Weeen-er!” After making the trip with no problems whatsoever, we figured that it had been a good buy – that we were weeners. The fact that we had just gotten two dachshunds led to the further name corruption.
My wife named our '92 Honda Civic Wondercar after driving it from IN here to WA state in the middle of February. It just keeps going, like the postal service (neither rain, nor snow…). A wonder of automotive engineering.
Finally, the Hyundai Tuscon we bought recently is named Armadillo, 'cause that’s a fair description: it’s silver, kinda bulbously funny-shaped, and is only seen on the dusty roads around these here parts. Name choice influenced by memories of my wife’s mother, who hailed from TX and had a stuffed armadillo when my wife was a wee lass.
I have a 94 Thunderbird LX named Erica and an 89 Thunderbird Supercoupe named Angelina. I usually just call them the LX and the Supercoupe though. And my sportbike, if not simply the bike, is the blue rocket or something along those lines. I haven’t named the dirt bike. It should have hospital in its name since everyone that rides it hurts themselves.
I don’t make a habit of naming my cars, but I recently got my motorcycle plate. The license number starts with JB, so I’m tempted to call it Jonly. If you’ve seen or heard Henry Cho’s stand-up act, you’ll know why. 
Sometimes I do, sometimes I don’t. One I did was my grey Chevy Cavalier, which I named Rosinante for Don Quixote’s horse.
My former car, a '76 Chevy Nova: The No Go. (That’s how it got to be in its final days.)
My current car, '89 Dodge Daytona: The Dodgy Daytuna. (Dumb, but what else is there?)
We had a Ford extended “Club Wagon” (a huge van with two gas tanks that held a total of 55 gallons of gas, which got about 15 mpg on the highway when fully loaded) that I called the Big Brown Behemoth.
I knew someone who had a blue Horizon named Beyond.
Sir Montague the Miniscule (Monty the Mini 1000)
Alex (Honda Civic LX, License plate LX___)
Spuds McKenzie was the motorbike (he was a party animal).
Dad got a big red thing, I said he should call it Carmine (Car, mine) he sold it instead.
My first car was the 1980 Omni. Which, in 1985, when I started driving it, I called “The Beast.” The name was chosen with malice aforethought. A car further from the powerful, intimidating image that the name “The Beast” conjures is hard to imagine. The Beast chose to avenge itself on a back road just past the Stow Country Club. The front transaxle separated while I was navigating an S curve. My first hint of a problem was when, in my perception, this one tree wasn’t moving out of my field of view as I turned the wheel. Then we hit, and rolled. I wasn’t hurt, but it was a revelation to me. Cars can be good or bad.
And don’t mock the 2-3000 lb death machine. (Since then I’ve always referred to Omnis as Deathmobiles, and refused to ride in one ever since. We got a letter from Chrysler that amounted to, “Nyah, Nyah - can’t sue us, we already recalled X number of this model for the bad transaxle problem.” I don’t much care for Dodge vehicles, either.)
My next car was something we got used from a friend of the family. And somewhat ironic. After that letter from Chrysler, I wanted nothing to do with them or their vehicles. But this car was a '77 Dodge Aspen Wagon. I used to joke that it was the perfect Boston driving vehicle. Solid enough to win a head on collision with anything short of a Mack Truck. And it was an 8 cylinder engine. It got something like 12 mpg highway. But I was safe in her. I named her after a story I remembered from Donald J. Sobol’s collection of sea stories. About a ship that was claimed to have been found drifting, lifeless in the North Atlantic, the Octavius. I called her Octavienne, to make it clear she was female. An old battle axe, but she always got me home safe.
After that, I did without a car for a while. Then while I was in the Navy I needed to get a car. So I bought a 1989 Ford Escort of a fellow sailor. He brought her to Florida from California. So she became Calafia. Shortened to 'Fia. My sister freaked the first time she heard me call my car that: She had a friend whose name was Fia, who had a reputation for being a bit wild. She thought I’d named the car after her friend.
After Fia finally died, I ended up picking up a 1997 Ford Escort Wagon. I like wagons. Alas Mirai is dead.
And I’m currently carless.
First car was a 74 Beetle, which was called “The Formula Vee” (alternately, “Formula Veeeeeeeeeeeeee”) because that was on the side of the car when I bought it. It was some sort of dealer package.
Next came a 80-something Toyota truck. Extra cab, long bed, no power steering. It was a tough parallel park, and once while doing so, I turned to my passenger and complained “This thing is a whore to park!” Henceforth known as The Whore.
Finally, a 97 Subaru Impreza Outback. When I got it, I worked with a bunch of women who liked to tease me about liking science fiction. So I named it the Millennium Falcon and made them make Chewbacca noises when they were in the passenger seat.
Count one more for having a “Beast”, though mine was actually deserving of the name. A '77 Grand Prix with a rebuilt engine that was WAY more powerful than anything a 16-year old should have learning how to drive. The miracle was that my brother and I managed not to kill ourselves carrying too much speed into curves, plowing into cars from behind, or anything else that comes from being a scatterbrained teenager.
The funniest bit is that after the Beast met its inevitable end (engine failure, not an accident), it was replaced by an '83 Le Car, much closer to the Omni in aspect, which we affectionately and somewhat sarcastically called “The Beastlette”.
Alas, any of my more recent cars have resisted nicknames.
My first and current car, a 93 Subaru Impreza, is unofficially named Voldemotor. I guess it’s secretly an evil car?
