Mr. Bean’s car also fits him. Atkinson was influenced by Tati/Hulot.
The “Mod Squad” was recruited to blend into the underworld by way of their (supposed) edginess and coolness, an image compromised by always arriving on the scene driving new Ford station wagons, because Ford was the sponsor.
BEST
Mad Max’s Ford Falcon GT “Pursuit Special” – “Last of the V8 Interceptors”
KITT from Knight Rider-- a 1982 Pontiac Firebird Trans Am
The producers of the various Batman incarnation did well designing the Batmobiles to match the depiction of the Batman character.
Also using a DeLorean as a time machine in Back to The Future was brilliant
The 1975 green Ford Taunus from the 1999 German cult comedy “Bang Boom Bang” (note the licence plate. DO is for Dortmund). It fits perfectly, exactly the car a guy like Keek at that time (1999) and that place (Unna/Dortmund in the Ruhr region) would drive.
Looking back, the car casting in Little Miss Sunshine is kind of unrealistic, and pretty clearly contrived to force the entire family to go along on the road trip to the pageant. I mean, what kind of mom with two kids drives a Miata, when the family’s only other vehicle is a VW van that she can’t drive because it’s a stick? I could see it as a “weekend car” along with a more practical one, but I can’t see how they can possibly get by with that being the only vehicle she’s able to drive.
On the good side, Mannix for the most part had good cars. The 'Cuda and the Dart were good, the red chevy boat…not so much.
On the bad side, Nash Bridges’ 71 Hemi Cuda convertible. It was all well and good that Sonny Crockett drove a $100K Ferrari - he didn’t own it. But I guess they thought Johnson needed another $100K (at the time - much more now) car for his new show. But a classic muscle car for someone that gets in car chases and gets shot at? In the holy name of Detroit, take that car away from him before he destroys it! (yes I know it’s off the air.)
Homer Simpson was the perfect person to buy a Canyonero:
I’ve read that Patrick McGoohan objected to anything that made Danger Man more like another James Bond: sensationalized sex but also gadgetry, wanting it to be more like The Spy Who Came In from the Cold. So when he made The Prisoner, instead of a tricked-out Aston Martin he drove the Lotus: basically a frame, suspension and power plant.
Actually, Nash Bridges might be back on the air; they’re working on a revival.
I will have to nominate the Beverly Hillbillies, Oldsmobile 64 as best casting.
No words need be spoken. 
Just happened to see The Kominsky Method has some new episodes so I watched a couple and thought of this thread. Sandy’s vintage Mercedes is perfect for his character. I don’t recall if his car has been discussed in the show but my impression is…he was a pretty big actor back in the day and bought a flashy car which he is still driving now that he has a much less high profile life running an acting school. He has hung on to it through rough financial times and divorces because he loves it and it fits him.
According to IMDb it is a Mercedes-Benz W111, Model 280 SE Cabriolet, circa 1969. Only 1,390 were built.
In one of the episodes I watched tonight he proudly points out that it has a cigarette lighter and at least two ashtrays.
I nominate George Costanza’s 1983 Chrysler Le Baron—a clunky, unattractive car which George loves because he thinks it was owned by Jon Voight.
In the original Adventures of Superman Clark Kent drove a Nash Healy. Absolutely the wrong car for a mild-mannered reporter whose main goal was to be inconspicuous.
Jon Voight the actor?!? 
That’s funny. I was watching that today and came here to post the very same thing.
The only other web site I visit (yeah, I spend too much time here) has an article on an excellent example of “worst”…
Bonus: the article’s by Jason Torchinsky.
Read everything he’s ever written, and watch him buy and rehab weird Japanese cars (Nissan Pao) and the cheapest EV (the Changli).
But George Reeves played him as a really interesting guy. Cool double-breasted suits with crisp fedoras, a classic convertible, and he walks in his apartment and plops his hat on a funky mannikin head (that he greets with “Hello, Arthur!”… not sure about the name).
Kowalsky’s 1970 Dodge Challenger in Vanishing Point. A dream car for a dreamlike journey powered by amphetamines.
Not a car, but Captain America’s chopper in Easy Rider
BEST:
The Long Haul (1957) – Leland 8-wheeler – Now that’s truck performance:
It Started with a Kiss (1959)– The Lincoln Futura - later to be turned into the TV Batmobile - the best and only good thing in the film:
The Party (1968) – 1933 3-wheeled Morgan driven by that great Indian actor, Hrundi V. Bakshi (Peter Sellers):
Danger: Diabolik (1968) - E-Type Jag; there is actually an underground lair full of them (most were cut-out from magazine ads). The perfect car for a supervillain:
Joanna (1968) – Bizzarini; the heroine dates a rich Italian:
UFO (1970) – Stryker’s car; TV series with awesome vehicles:
http://epguides.com/comics/shado/
Tucker: The Man and his Dream (1988) – Tucker; unassailable casting of the cars.
WORST:
War (2007) - Spyker C8 Spyder
Just the car a mysterious assassin would drive to avoid being conspicuous.