(MONEY Magazine) – Among my road rules: Anyone who loves cars must own at least one convertible before he dies. Even if he lives in Duluth.

That canon has become more sacrosanct in recent years.

Dispensations could once be granted considering the shortage of affordable ragtops--and the surplus of the finicky English variety destined to collect more cobwebs than miles.

No more. Whether because of global warming or a similar effect on the public heart, convertibles are legion. They're safer, more practical and better built than before. And thanks to tighter-fitting softtops and the rise of retractable hardtops, winter hybernation is no longer a must.

Now don't even start with that "mid-life crisis" stuff. Chances are, all those AARP members began dreaming of a convertible around, oh, age 16--it's just that they're finally playing with more than Monopoly money. Why begrudge them the pleasure? The truth is, no car, and certainly no SUV, can touch the romance and adventure of a convertible, the possibilities that open up the second you open that roof. With the alfresco driving season in full swing, we road-tested five of the latest models, from a $20,000 retro roadster to a Teutonic fantasy at nearly $134,000. Ready for sun on your face and wind in your hair? You'll find these willing partners.

PT Cruiser Convertible

If your goal is a fun, practical convertible with four adult-size seats, the softtop PT is the best game in town. Its humongous back seat offers 10 more inches of legroom than in convertibles like the Ford Mustang or VW Beetle--more legroom, in fact, than any mid-size sedan. Rear seats fold and tumble, extending the smallish trunk into the cabin. I managed to slide 40 moving boxes, folded flat, inside; a pair of golf bags fit lengthwise with room to spare. The convertible also out-styles the hardtop, with long coupe doors that complement the PT's retro lines.

The $19,995 base model gets a modest 150-hp, 2.4-liter engine. Nice price, but the base PT engine has always felt underpowered. Stepping up, the $23,490 Touring model adds a turbocharger for 180 hp, or 220 in the lavish GT Turbo edition ($28,155).

Resembling a Hot Wheels hearse, my jet-black GT was fleet, nimble but thirsty for an affordable compact, managing 19 mpg (EPA figures say 21/27 mpg city/ highway). For cash-conscious PT fans, Touring models strike the best balance of price, power, features and economy.

Lotus Elise

In a world of overweight, overstuffed sports cars, the Elise is a revelation.

England's Lotus is importing its first new model to the U.S. since 1990, and a bamboo raft would suffice to carry this exotic beauty ashore. The tiny Elise gets only 190 horsepower from its 1.8-liter Toyota engine mounted behind the driver but weighs just 1,975 pounds, thanks to its ultralight yet strong aluminum structure. How light is that? A little Mazda Miata roadster weighs over 2,400 pounds, roughly two NFL linebackers more than the Lotus. Such a power-to-weight ratio lets the Elise run from 0 to 60 mph in a fiery 4.9 seconds (while managing 37 highway mpg). More important than pure speed, Lotus' renowned racing and engineering skills produce a car with balance and reflexes akin to a $200,000 Ferrari's. During my testing at Barber Motorsports Park in Alabama, the Elise outran a 315-horsepower Porsche 911 around the challenging circuit. It's the rare production car that's truly at home on both street and track.

Yet the question persists: Is the Elise a bargain at $39,995 or an overpriced bauble? Certainly, there are several better-established players around the same price. All are more suited to everyday use, with more accommodations to comfort than the Lotus--a bare-bones go-cart for the street. Lotus is gearing up its 39 U.S. dealers to support the Elise, but it's hard to imagine service as convenient as oil changes for your Civic. Finally, only about 2,200 Elises will reach our shores this initial year. So expect the usual price premiums in the giddy early stages.

Bottom line, only fervent, hard-core drivers will want an Elise. After one drive, they'll want it desperately.

Audi S4 Cabriolet

The Audi A4 is a paragon of design and craftsmanship, but the latest generation has also upped the luxury and heft while downplaying the sport. There's no such trade-off with the high-performance S4 version, thanks to the A8 sedan's 340-horsepower V-8 burbling under the hood. Following its sedan debut, the S4's muscle makeover extends to the two-door Cabriolet.

It's almost too good to be true--such a lovely, sweet-natured convertible, yet so ferocious when cornered by roving BMWs. Reality intrudes with the price: $54,570 with the six-speed manual transmission, or scraping $60,000 with a handful of options. That's one expensive Audi, a brand whose resale value has historically trailed that of top luxury makes.

The S4 soothes the pain somewhat with standard Quattro all-wheel drive, which helped it make quick work of rain-washed roads during my testing in New York's Hudson Valley. When the clouds part, the Audi's three-layer insulated softtop powers open in a methodical 27 seconds to reveal a roomy back seat and a cabin that may set a new standard for suppressing wind and noise.

Happily, the engine's sweet 4.2-liter song is still heard, transporting the S4 from 0 to 60 mph in a scant 5.8 seconds. The ready thrust is welcome in a solid but portly convertible that weighs nearly 4,100 pounds (closer to 4,200 with the six-speed Tiptronic automatic).

The payback on the manual version is low mileage, 15/21 mpg in city/highway driving, which nets a $1,700 gas-guzzler tax. Automatics reach 18/23 mpg, avoiding the tax. The Audi rides and handles beautifully, though the steering still feels a bit numb and distant when pressed to the limits.

Like the pricier BMW and Mercedes, the Audi integrates protective steel hoops in the rear deck that instantly deploy if sensors detect a rollover; they combine with an ultrarigid windshield frame to maintain an intact survival zone if the car ends up on its roof.

The S4 amply satisfies open-air buyers who reject any trade-off in luxury, comfort and performance. As with our next two convertibles, such satisfaction today comes at a price.

BMW 645 Ci Convertible

A survey in a German car magazine reported that BMW drivers have more sex than owners of any other brand. And while they can forget any assignations in the 6-Series' cramped back seat, the car itself is a rolling testament to libido, all arresting curves and voluptuous proportions. It's a worthy successor to the original 6-Series, a long-limbed coupe that won a passionate U.S. following over a dozen years from 1977 to 1989. Now the prodigal 6-Series is back, at a coldly modern price of $76,995 for the 645 Ci convertible, a $7,000 premium over the coupe.

And as with the 7- and 5-Series, the broken-record debate over BMW's edgy new styling has overshadowed the larger point: The new models have defended their status as the choice for luxury buyers who love to drive.

From the boulevards of Beverly Hills to the snaking canyons north of Malibu, the wide-bodied BMW was in serene command. It's a technological tour de force, starting with the rousing 4.4-liter, 325-horsepower V-8 that sends the Bimmer from 0 to 60 mph in 5.7 seconds. That's with a six-speed manual shifter, something most luxury competitors don't offer. The manual version's 15/23 mpg in city/highway driving nets the gas-greedy tax ($1,300); no tax on the six-speed automatic, at 18/26 mpg.

The ride is magic carpet, the performance otherworldly. Electronic aids include active roll stabilization, uncanny at reducing body roll in fast corners.

A $2,800 sport package adds dramatic 19-inch wheels with run-flat tires, along with the groundbreaking active steering: It quickens the steering ratio (in other words, less wheel rotation is required to produce a given amount of turn) to ease parking and boost agility. I'm pretty much sold on the advantages, but there is a minus: The steering needs to send more direct feedback to the driver. The car eats corners like an Atkins disciple eats bacon, but it sometimes seems to pilot itself--not the sensation BMW drivers crave in their ultimate driving machine.

The sculpted softtop looks good even when it's up, and its clever power rear window raises or lowers independently of the rest of the roof; it functions to block the wind or to let in a breeze when the top is closed.

Top down, the BMW provides efficient trunk space, plenty for two golf bags. Complaints? The notorious iDrive knob that purports to handle audio, climate and other chores has been simplified, but it's still an indefensibly poor design.

The low-slung roof does impinge on back-seat space, but at least it exists, as opposed to the virtual parcel shelves in rivals like the Jaguar XK and Lexus SC 430. It's tight for six-footers but, as BMW notes, it's really for "occasional" use.

Mercedes SL600

The V-8-powered Mercedes SL500 is already a modern classic, a cut above roadsters from Jaguar, Lexus and Cadillac. The SL600 just rubs it in. With two turbochargers, 12 cylinders and a shocking 493 horsepower, this Benz is like lighting your Cubans with $100 bills--effective but verging on overkill. Or maybe I'm just jealous. I certainly loved every mile in the SL600; rocketing around like a billionaire Buck Rogers and clocking the speedy 15-second retracting hardtop are easy distractions from the $133,860 price. That price is, ahem, about $40,000 north of its V-8 sibling. Yet whether the Benz is "worth it" is moot. This is a statement car, the statement being that the owner liked one and bought one, the way you or I might shop for socks.

Those folks will discover a two-seater that explodes from 0 to 60 mph in 4.0 seconds, easily outpacing your garden-variety Porsche or Corvette. From there, the Benz bullet-trains to its electronically limited top speed of 155 mph as quickly as your right foot, common sense and lurking-police anxiety will allow. Yet it's as smooth and comfortable in rush-hour traffic as at autobahn speeds. As with the BMW, the safety list is endless, the tech trickery dazzling, if occasionally offputting in its complexity. Handling and braking are incredibly capable, though the electronic brake system takes getting used to--it feels touchy at low speeds. The SL600 also returns 13 mpg city/19 mpg highway, a Hummeresque score that earns a $2,600 gas-guzzler tax from Uncle Sam. Though something tells me the person who can afford the payments won't be feeling much guilt at the pump.