The overkill machines from BMW's M and Mercedes' AMG divisions always make a lead paragraph exciting, which is why I’m going to mention the phrases “tri-turbo diesel” and “Cold War relic with 612 horsepower.” That is a cheap shot, and I'm not ashamed to use it on you. The Mercedes E63 really is my favorite sedan in the world, and no doubt you’d like to stop reading and see the monsters behind those links. Very badly.

Anyone who loves cars knows what I mean. But while we appreciate the German obsession for ludicrous speed, the average car buyer can’t relate. What about real-world performance, the kind that simple, factory bolt-on parts offer, but for the price of colored Porsche seatbelts and wheel caps?

These four cars below fit that description. Whether installed by a dealer or mixed and matched with your own two hands, these parts squeeze more speed for relatively modest cost -- and without voiding your warranty.

Volvo XC70 Polestar

The New England mom wagon I’m driving this week has a factory hot chip, a reflashed electronic control unit that boosts power and torque without compromising fuel economy. The ECU is a cheap, easy part to modify, since spark timing and other critical engine variables can be changed instantly with just new software. 

The $1,495 upgrade, developed by Swedish tuner Polestar (which also builds Volvo race cars) boosts horsepower from 300 to 325 and torque from 325 to 355 lb-ft, and lowers the peak torque rmp. A similar upgrade is available on the rest of the Volvo lineup; you’ll know it’s a racier Volvo from the powder-blue badge on the rear. Once the transmission wakes up, the XC70 Polestar is pretty darn quick -- not to mention pretty. Because there are no suspension or transmission upgrades, I think the Polestar package makes more sense on the C30 or S60 T6, which features adjustable steering weighting and stiffer springs.

Honda Accord HFP Coupe

The current Accord coupe, a rare sight anywhere, is a handsome reminder that Honda does make exciting cars. It’s available with a 6-speed manual transmission and a V6 engine, an almost-extinct combo nowadays. The HFP (Honda Factory Performance) edition is a subtle, grown-up upgrade versus the young-and-wild CR-Z Mugen.

But unlike the CR-Z, the HFP upgrade actually upgrades the performance beyond side skirts and chin spoilers. The $3,443 package, installed by a Honda dealer, also drops the ride height by more than half an inch with firmer springs and shocks. Together with 19-inch alloy wheels and tires, the Accord HFP, already with 271 horsepower, is a good fill-in now that the S2000 is gone. For real savings, just grab the $885 suspension kit and throw on some gummier tires.

Ford Fiesta B-Spec

The World Rally Championship does not stop in America, and, as with soccer, Americans don’t seem to notice the sport’s insane popularity elsewhere. But that doesn’t mean you can’t build your own Fiesta rally car from scratch and run it in the New England Forest Rally. For $38,795, plus the cost of a Fiesta, you can.

If you’re not interested in a full-on race car, B-Spec parts are available piecemeal from Ford Racing. Try your hand at short-throw shifters ($200), high-flow mufflers ($739), autocross suspension kits ($993) -- even an option to remove the air conditioning ($99). It doesn’t get much easier to show up at an SCCA track event, have a blast and drive home.

Toyota FJ Cruiser TRD

The FJ is the only cool Toyota. The retro styling, which has real roots like the Jeep Wrangler, stands for serious off-road cred (so do its three windshield wipers). All the better, then, to install a supercharger from Toyota Racing Development on the 4.0-liter V6 engine.

It’s a decent boost, from 260 to 304 horsepower and 271 lb-ft of torque to 334. The $4,500 kit comes with a reflashed ECU, an intercooler and high-flow fuel injectors; get it installed at a Toyota dealer or you’ll lose most of the 60,000-mile powertrain warranty. If you’re staying on-road, grab some 4-piston TRD brakes and performance pads. For big, bad-boy dirt tires, the 16-inch copper bead-lock wheels are too sick for words.

Clifford Atiyeh has spent his entire life driving and riding in cars he doesn't own. He was raised in Volvos and has grown to love fast, irresponsible vehicles of all kinds. He lives in Boston, is a member of the New England Motor Press Association, and has reported for The Boston Globe, Car and Driver, Popular Mechanics and The Times of London.