Suppose you want the ultimate road car: a striking machine that handles like a racecourse champion, pulls a g on the skid pad, and rockets to 100 miles per hour in less than eight seconds.

A generation ago, you could have imported your own specialty car from Europe, making it street legal by modifying the lights and adding seat belts. These days, stringent safety regulations mean you’d have to put your baby through a battery of emissions and crash tests—impossibly expensive, not to mention the fact that the car would be totaled.

Alternatively, you could spend about half a million dollars on one of the few hundred road rockets produced each year in California by Steve Saleen. Or you could shell out a similar amount for a legitimately imported European supercar. But for even better handling at a fifth of that price, there’s just one way around those pesky federal restrictions: Import your own Noble—or at least import most of one.

Working-class hero Lee Noble’s company is one of more than a dozen specialty carmakers in the U.K., which exempts low-volume carmakers from compliance with some of the tests required of high-volume manufacturers. That’s allowed Noble to spend the past 20 years handcrafting some of the fastest, most audacious, and best-handling vehicles in the world. His cars are worshipped by auto lovers, and only several dozen of them are sold each year.

The only way to get your own Noble in the U.S. is to buy the rolling chassis of one of the most popular models, an M400, for $66,900. That’s less than the price of the finished car in the U.K., but then you do need to do a bit more work before you can drive it. The chassis has suspension, brakes, wheels, and tires, and it’s assembled, painted, and outfitted with a full interior. You could call it a car minus the engine and transmission, but that wouldn’t please the Feds, who officially view it as parts.

Next, you need to assemble your Noble. Hire a mechanic—a selected and factory-approved one, please—to install the loud parts. The standard recommended engine is a 3-liter Ford Duratec V-6, to which you can add twin turbochargers and a Getrag six-speed transmission. Though it may take up to 100 hours to put the thing together, the total tab for the rolling chassis, engine, and transmission plus installation should stay just under six figures. The performance of the resulting vehicle will humble cars that cost five times as much. It’s a classic recipe: A low, agile, and lightweight car doesn’t need massive power to beat much heavier cars. A Noble M400 weighs just 2,320 pounds with running gear— that’s less than a Mini Cooper. So the 425-horsepower engine rockets it from zero to 60 miles an hour in just 3.5 seconds, which is faster than a $170,000 Ferrari can manage. (See more fast cars in the slideshow.)

Better yet, the Duratec’s not a pricey engine. Millions have been made and fitted to cars from the Lincoln LS to the Ford Taurus, meaning parts are reasonable (no $180 Ferrari oil filters here). And hey, if you blow it up, you can afford another one: A brand-new Duratec (without turbos, manifold, and other extras) costs $4,400.

Now, the M400 is hardly luxe. The windows are wound by hand and roll down only two thirds of the way, though air-conditioning is standard. The dashboard, switches, and knobs are lifted wholesale from European economy cars, and the interior is swathed in Alcantara faux suede. Owners tend not to mind; they know they’re not buying a Bentley.

Scott Sommer, a semiretired Minnesota businessman who has raced at an amateur level for years, is one of the rare few who built the car himself. “The competitors to this car are exotics that cost six to eight times as much,” he chortles. “If you’re not concerned about impressing the neighbors with a Ferrari or Lamborghini, the Noble is a wonderful choice.”

Noble’s engineless creations have done well by Dean Rosen, owner of 1G Racing in Hamilton, Ohio. His roots are in selling Shelby Cobra replicas manufactured in South Africa. After Noble chose to build his namesake cars at the same South African plant and Rosen found out that Noble’s cars went to the U.K. minus engines and transmissions, lightning struck.

Rosen sold the first Noble “kit” in the States almost three years ago. Now he moves six chassis every month—as many as he’s allowed to import—and has a steady three- to four-month backlog of orders for them. To date, he’s sold 220. He estimates that 70 percent are used on the street, with the rest reserved for racing.

So is this really legal? In a word, yes. Every state allows people to create their own cars from scratch—usually hot rods or fiberglass kit cars. While the paperwork and details vary, the process is the same: You build the car, then the state inspects it for roadworthiness (lights, brakes, etc.). Rosen notes that his company has helped owners title their Nobles in almost every state. Once your Noble passes inspection, the D.M.V. will give the car its own 17-digit vehicle identification number, which will allow you to insure it. And away you go.

But don’t even think about trying this with that luscious Ferrari you saw in Italy. If the car has a V.I.N. or is from a manufacturer who imports into the U.S. already, you’re out of luck—and out of speed.