Spring cleaning has nothing to do with the junk in your basement, of course. It's all about re-habbing your image and sprucing up karma. It's about trimming sideburns and thinning the winter thatch—or re-contouring the comb-over, at least. Most emphatic of all, it's about popping the top off a new convertible and catching flies with your teeth while dogwoods bloom and pollen clouds eddy in your wake.

Don't tarry, now. Summer's triple-digit humidity is only a few credit-card billing cycles away. To make it easy, Ford has conveniently introduced a stunning convertible version of its newly made-over Mustang just in time for April's showers, whereas Dodge's doughty Viper roadster bleats blood-stirring mating calls through red-hot side pipes. Oh, the games we could play...

2005 Ford Mustang Convertible

It's pretty simple, really. If you want to make a popular sporty convertible, start with a popular sporty coupe. Since its introduction last autumn, Ford's 2005 Mustang is so hot that it's scorching the sales charts. For the first quarter of '05, Ford reports selling 16 percent more new Mustangs than in the same period last year. The original "pony car" is the brightest light in Ford's firmament lately, and the car is winning justifiable praise for its shrewd combination of styling, performance and value.

This trio of secret ingredients remains intact in the new Mustang convertible. Available with both V6 and V8/GT powertrains, Ford's new drop-top retains the muscular styling that reminds so many boomers of Steve McQueen impersonating a Bullitt in the streets of San Francisco. Instead of the coupe's swooping fastback silhouette, however, the Mustang convertible features a more classic notch-back roofline that nevertheless integrates naturally into the sculpted retro-contours of the car.

2005 Ford Mustang Convertible

With the top up, the Mustang cabrio is noticeably bereft of wind noise. Visibility is great, thanks to retention of rear quarter windows and a broad rear window, or "backlight." With the flip of two latches and the push of a button, the top drops in 13 seconds flat. A clever Z-fold maneuver packs the roof into a shallow pocket behind the rear headrests, with the upper surface of the leading edge providing a nice, finished appearance for the whole bundle.

Designed simultaneously with the coupe version, the Mustang convertible benefits from integral stiffness that is the envy of other open-top car designers. Torsional, or twisting, stiffness is more than double that of the previous Mustang convertible; and bending stiffness is 50 percent more rigid. This, naturally, translates into superior handling with excellent feedback from the road and predictable, stable reactions while cornering. Just the same, suspension tuning is ever so slightly milder than the coupe's, in consideration of convertible owners' typical preference for boulevard cruising over backroad barnstorming.

There's no backing off underhood, however. The convertible GT boasts a 300-horsepower 4.6-liter V8, whereas the V6 model extracts 210 hp from 4.0-liters. Both blocks are single-overhead-cam designs, and both feature seductively tuned exhaust notes guaranteed to froth the blood, particularly with the top down.

Mustang's makeover has resulted in significantly better comfort (i.e., legroom) for rear-seat passengers, and thanks to compact packaging of the folded top, trunk space is relatively generous at almost 10 cubic feet. Although these are hardly SUV-type specs, the four-passenger Mustang convertible is far easier to live with in real-world circumstances than many other cramped rivals.

It's far easier to afford, as well. The base prices of two Mustang V6 convertible versions range from $24,495 to $25,300, and the V8/GT models start at $29,995 and $31,175. Few if any other soft tops can be said to offer this much bang for the buck, which is no doubt why this galloping bronc is already stampeding out of showrooms only weeks after its debut.

2005 Dodge Viper SRT-10 Roadster

Everything about the 2005 Dodge Viper supercar is intimidating. First and foremost, it's a challenge to the very source of one's pride. Its mere presence bristles with affrontery: "Look here!" it snarls. "Touch me if you dare."

It's too simplistic to describe reactions to the Viper SRT-10 roadster as merely visceral. The entire form of the car displays archaic, archetypal body language overflowing with invective and boast. With 8.3 liters of V10 engine underhood, with its cramped two-seater cockpit and tiny rear deck, the Viper swaggers like a medieval gallant in codpiece and leather jerkin. If you don't like this car, you don't like cars. Period.

Everything about the 2005 Dodge Viper supercar is intimidating. First and foremost, it's a challenge to the very source of one's pride. Its mere presence bristles with affrontery: "Look here!" it snarls. "Touch me if you dare."

There are 500 horsepower on tap and 525 foot-pounds of torque for custom-striping the pavement with sticky black burnouts. Zero-to-60 is a less-than-four-second fling; and zero-100-zero takes all of 12 seconds. Even so, at 90 mph in sixth gear, the motor is turning only 1,500 rpm—idle speed for the cars of mere mortals.

Viper's steering is snake-bite quick, and the hard-braking Brembos are a prescription for detached retinas. The throb of exhaust is at once deafening and infatuating. And terrorizing to wives: Despite a perfectly legal sprint to 50 mph, though gears one and two, The Wife quailed at the apocalyptic retort of V10 fanfare and the weight of sudden G-forces at the sternum. "Have you stopped beating your wife?" my friends are now prone to say.

For '05, Viper's current roadster is unchanged since its 2003 debut. A new coupe awaits in 2006. The SRT-10 Viper convertible is one of the fastest production cars available in the world. At $84,495 as-tested (including the $3,000 gas-guzzler tax), it is not one of the least expensive; but among its rarefied peers, it does rank as something of a bargain. It also ranks as an inimitable automotive experience, able to transform a mere week's proximity into a subsequent lifetime of unrequited pining.

For '05, Viper's current roadster is unchanged since its 2003 debut. A new coupe awaits in 2006. The SRT-10 Viper convertible is one of the fastest production cars available in the world. At $84,495 as-tested (including the $3,000 gas-guzzler tax), it is not one of the least expensive; but among its rarefied peers, it does rank as something of a bargain. It also ranks as an inimitable automotive experience, able to transform a mere week's proximity into a subsequent lifetime of unrequited pining.