Americans have always wanted to hit the road and leave their emotional baggage behind, splurging for the more than 8 million RVs now on the road.

But they've always wanted to take their physical baggage with them, so RVs keep getting bigger, more luxurious and, of course, more expensive. The top motor coach at this week's Denver RV show is polished to a glare meant to distract from the retail price of more than $600,000.

Now the new generations of recreational vehicles and their amenities have come full circle to be just as versatile — and just as demanding — as the stationary homes so many of us want to escape.

RV shoppers seek clean-burning diesels with higher gas mileage, pop-out living rooms wide enough for matching BarcaLoungers, Corian countertops, rooftop solar panels and camping spaces with built-in patio barbecues.

Condo-ized parking spaces for RVs in Highlands Ranch are selling for $120,000 each at a development that may be the first community named for its parking spots instead of its elm trees. A share in GarageTown comes complete with its own clubhouse for RV owners exhausted by all that waxing.

Fractional ownership has come to the RV business, mirroring purchases of mountain real estate. Baby boomers eagerly pay $30,000 for a five-week share in a motor coach. Buyers add $300 a month in "maintenance fees," and a management company hangs up a set of prelaundered, monogrammed towels for each owner upon arrival.

And RVs now come with their own garages. The most popular style at this year's RV Adventure Travel Show at the Colorado Convention Center is the one with an enclosed toy-parking area at the rear.

Buyers cram motorcycles, ATVs, kayaks or just an extra load of firewood in the back, then electronically fold down extra bunk beds to fill the "garage" space once they unload at their campsite.

"Parks" inside RV parks

Meanwhile, RV parks now offer "concierge" service — yes, ma'am, there is Salisbury steak at the early-bird special — and are renovating to accommodate the extra-wide pop-outs that turn a mere trailer into a manse. They're even creating real urban-style "parks" within their RV parks, responding to vacationers who demand views of green space instead of just the generator next door.

The latest perks may be the final evolution in a lifestyle that caters to people who want to get away from it all so long as they can bring it all with them. The first generation of RV buyers, following World War II, saw their campers as a frugal way to roam. The postwar baby boomers, who already make up the biggest segment of RV owners and officially start retirement on Social Security this year at age 62, saw RVs as "a way to fulfill their needs and their wanderlust," said recreation author and full-time RV resident Carol White.

Now, the fastest-growing segment of buyers are families with young kids who demand adventure launched from the comfort of a rolling home.

"Whatever their particular sport is, they put those toys in the back end," White said.

(The Fuzion RV available from Jim Humble of Windish RVs at this year's show also comes with its own "gas station": a tank and pump in the back that can fuel up those empty motorcycles.)

Steve Acker of Brighton, 51, bought a $22,000, 27-foot camping trailer after last year's RV show. Old story: Man loved camping, woman hated camping much more than man loved camping. For the first 15 years of his marriage, Acker's wife said, "You'll never get me in a tent."

They considered buying a mountain cabin, but now they have a "cabin on wheels" with a "different view every time," and they take their 12-year-old son all over the country, Acker said.

The allure is obvious "Even our dog loves it," said Acker, echoing expert assessments that a prime draw for baby boomers is taking pampered pets everywhere. "She gets hyper as soon as we start loading up." His wife? No, the dog. But still, the allure is obvious.

Acker's parking space is a bargain, $30 a month at a farm a mile down the road where an elderly couple offers eight RV spaces. He's not planning to condo-ize his RV parking, but plenty of others are, quickly selling out GarageTown developments at $96,000 to $161,000 a slot in Loveland, Highlands Ranch and elsewhere on the Front Range. An HOA-style fee to keep the lights on and toilet paper in that clubhouse adds $45 a month to the cost.

"It's not for everybody, that's for sure," said developer Mike Ard, who also sells spots to car collectors and small-business owners parking delivery trucks. "But we're finding that people are willing to pay the price to protect their investments."

Despite the RV fans' desire for escape and adventure, this is the year those travelers may choose to bring some of that emotional baggage on board for the trip. Life on Wheels, a popular traveling series of seminars for serious RV users, will offer its first-ever going-green seminar in March in Tucson.

"The good news is we can take effective action while continuing our enjoyment and enhancement of the RV lifestyle," says the flier from seminar leader Bob Difley. Coordinator Peggy Waterman, speaking from her RV in Florence, Ariz., said more drivers are interested in better mileage, greener septic chemicals, a new generation of clean-diesel "pushers," or engines, and eco-friendly building materials for the RV itself.

RVs with all-composite shells

New buyers are flocking to a van-conversion-size RV such as the Roadtrek, which gets closer to 20 miles to the gallon, rather than the 8 to 10 mpg in older haulers, said Recreational Vehicle Industry Association spokesman Kevin Broom. One manufacturer is working on an all-composite RV shell for lightweight driving.

The show-floor salesmen are learning to speak the lingo. Randy Ketelsen, whose Wheat Ridge family runs the world's largest pop-up tent dealership, said that the higher gas prices go, "the better we do." With solar panels optional on every pop-up tent, "all weekend long you camp on your solar battery power and the 20-gallon water tank you brought with you. It's a very good way to be a conservationist," Ketelsen said, smiling.

The RV show's producer, Jeff Haughton, knows even more of those magic baby-boomer words. "Away from home, your carbon footprint may even be smaller."