Workers walk around recreational vehicles at a Thor Industries plant. Photo: joshua lott/Reuters 
 
 For anyone who has gotten stuck on a mountain road behind a massive recreational vehicle, get used to it, there are a lot more on the highway. 
 
 Recreational vehicles, ranging from bus-sized motor homes to retro trailers, have been a boom-and-bust industry since they first became popular in the early 1970s. Now a wave of retiring baby boomers and a surprisingly young new fan base have sent U.S. unit sales above their housing boom peak. Shares of the two leading manufacturers of RVs, Thor Industries THO -1.08% and smaller Winnebago Industries , WGO -2.13% each hit records last week. 

 After shares of Thor Industries surged over 13 percent on Tuesday off a strong earnings report, President and CEO Bob Martin broke down the recreational vehicle maker's forward drivers for CNBC. 
 
 "It's the change of lifestyle, it's a younger demographic, it's an industry that's really reaching this younger buyer," Martin told "Mad Money" host Jim Cramer. "We're probably still ahead of the millennials, but Gen X, Gen Y, and we're starting to talk to the millennials." 
 
 Consumers are increasingly gravitating towards RVs — many of which now boast amenities like large refrigerators, televisions and Wi-Fi — as ways to live life, not just camp, Martin said. 
 
 "It's this change of lifestyle that you can use an RV to not just go to a campground, but go to a kid's game for baseball, soccer, lacrosse, concerts," the CEO said. "It's a lifestyle piece." 
 
 But camping still remains an important driver to the RV industry. Executives like Martin see tent camping and RV renting as "gateways" to owning RVs. 
 
 A study sponsored by the Kampgrounds of America, the world's largest operator of privately held campgrounds, showed that 61 percent of U.S. households, or roughly 75 million, "now include someone who camps." 
 
 "Those people are potentially our next buyers," Martin said. "They hit about 30 and they get tired of sleeping on the ground and ... they want a bed, they want air conditioning, they want something comfortable." 
 
 To Martin, renting RVs represents a more affordable way to break into the lifestyle, particularly since consumers who try "RVing" tend to do it again. 
 
 As personalization becomes increasingly important to consumers, especially those who travel, RVs come into the fold as a formidable solution, the CEO said. 
 
 "If they like it, they may buy an RV because you have your own linens, you have all your own food, you have your own comfortable pillow, your own fan, just your things that are always in your RV," Martin told Cramer. "So many of the rental sites, I think, are great gateways for us to capture a customer in the years to come."
– Two of the biggest manufacturers of motor homes saw their shares rise to record highs last week, and the Wall Street Journal sees two big reasons: retiring baby boomers and a younger set of "glampers" who have embraced the lifestyle. Winnebago and Thor both saw strong sales of their recreational vehicles, and the industry is forecasting continued growth over the next two years. The Journal, however, throws a few notes of caution: First, any kind of economic downturn or energy trouble could, as it has in the past, jolt the industry. And second, the younger set of buyers is generally embracing cheaper, towable offerings, as opposed to sleek and expensive RVs that allow buyers to live in them for extended periods, even permanently. Still, industry execs sound pretty happy. "It's the change of lifestyle, it's a younger demographic, it's an industry that's really reaching this younger buyer," Thor CEO Bob Martin tells CNBC. "We're probably still ahead of the millennials, but Gen X, Gen Y (are responding), and we're starting to talk to the millennials." Martin says while some RV buyers are ditching their homes for a more mobile lifestyle, the key to most sales still revolves around camping, and stats show that more Americans are becoming campers. "Those people are potentially our next buyers," he says of younger campers. "They hit about 30 and they get tired of sleeping on the ground and ... they want a bed, they want air conditioning, they want something comfortable."