Pimped-Out Car

Time travel not required for this trope.

Any car that's weighed down with several tons of aftermarket crap/improvements. Done well this can result in a Cool Car, especially if the car becomes really quick, or impossibly durable, or loaded with gadgets that actually do something useful—hydraulics may be cool on a Low-Rider, but you can't exactly fight crime with them. Unfortunately, where previously the misguided customizer could only fit an 8-Track and an imitation gold steering wheel, the onward march of technology also means an ever increasing amount of pointless electronic window-dressing can be fitted into a car, resulting in a Rice Burner.

Some of the improvements can even be mundane, like Cup Holders.

Not to be confused with a Hot Rod, which involves taking stuff out of a car and then stuffing a very big engine in.

Itasha is a Sub-Trope about adding otaku related pimping to the car.

For the clothing equivalents, see Pimped-Out Dress, Pimped-Out Cape.

Examples of Pimped-Out Car include:

Comic Books

Tank Girl. Several times, in fact! The movie even has a montage.
Archie once had a shiny new exterior installed over his beloved, beat-up antique jalopy. It didn't fool anyone for long because "Betsy's" interior was as broken-down as ever.
The Batmobile.
Sin City has its fair share as almost every car has a souped-up engine and is in prestine condition for vintage automobiles.

Film

All the cars in the The Fast and the Furious series.
The DeLorean DMC-12 from Back to The Future, seen above, which Doc Brown converted into a Time Machine because of its stainless steel construction and, of course, if you're going to turn a car into a time machine, you might as well do it with some style.
In Revenge Of The Pink Panther we see Clouseau's "Silver Hornet" - a Citroen 2CV with ludicrous add-on fins and other accoutrements. It falls apart into a heap in both scenes it's in.

Live Action TV

The entire premise of Pimp My Ride.
Naturally this is occasionally seen on Top Gear, although it's not always 'Pimping' in the true sense. For example turning a Renault Avantime into a Mitsubishi Evo beater was all about tuning the mechanicals not sticking TVs into the headrests. The cheap police car challenge, where they strapped paint guns, wheel spikes and numerous blue lights on some old bangers was more in the spirit, as was the amphibious car challenge where James May equipped his Triumph Herald with a detachable mast and a sail. In another episode Clarkson namechecked Pimp My Ride, declared the typical results to be ridiculous and then set out to 'Quaint My Ride' by stripping out the interior of an old Mercedes S-Class and replacing it with an interior based on his house - wooden floor, stove, wingback armchair and a bookcase.

Music Videos

In the music video Pretty Fly For a White Guy (not to be confused with the trope it named), the titular white guy added hydraulics to his car, which might have been a pinto.
My Chemical Romance's "Na Na Na" video. The Trans Am with a rocket launcher.

New Media

There's a website called Ultimate Taxi, and that taxi seems to fit this.

Video Games

An option for cars in Grand Theft Auto: San Andreas. Just make sure you store one in a garage to keep it.
Saints Row 2 had even more and better Car-pimping options than San Andreas did. The tricked-out rides that you can make truly are remarkable!
Ratchet and Clank: Ratchet's ship in Going Commando could be massively upgraded with weapons, boost, shield, that affected its exterior. Also some purely ornamental shape upgrades, and many different paint jobs that could be unlocked then purchased.
Rage Gives you upgrade options for engine, armor, suspension, etc.

Western Animation

Justice League: Flash did this with a full-sized van once.
In The Simpsons episode "Ice Cream of Margie (with the Light Blue Hair)", Homer has Otto pimp out his ice cream truck.
Family Guy Presents Laugh It Up Fuzzball has a pimped out TIE Fighter.
Mater from Tokyo Mater.
- Also, Kabuto, the short's villain. At the end of the short Kabuto loses to Mater in a race and as a result he is stripped of his modifications.

Web Animation

Poked fun at in the Strong Bad Email "Car", where Homestar tricks out his hat.