When Carlos Lozano and Hernando Londono started frying up Colombian-style hot dogs in a Sweetwater parking lot 10 years ago, they claimed two advantages over other eateries: They served authentic Colombian hot dogs; and they served authentic Colombian hot dogs after 3 a.m.

Since then, the partners' fast-food chain, Los Perros, has expanded to seven locations, and its success has spurred a host of imitators, Lozano said. Today, there are a handful of places in South Florida where you can get Colombian-style hot dogs and fried potatoes after a night on the town.

It's welcome competition, Lozano said.

``We just enjoy that people are copying what we're doing -- it makes us try to do something better,'' he said.

The copycats have not only pushed Los Perros to be innovative, but also to rapidly expand operations in order to capture a larger share of a niche market that had been more or less ignored by local fast-food joints before Lozano and Londono came along.

Here's a snapshot of Los Perros' average late night customer: young, fatigued from a night of dancing and drinking, and looking for a place to fill up on South American fare before calling it a night.

The restaurant-slash-nightclub caters to this crowd with pulsing music, comfy red couches and ``perros'' -- hot dogs topped with pineapple relish, spicy mayo and mozzarella cheese.

It's a popular combination that has allowed the restaurant to expand from a single hot dog stand in a parking lot to multiple locations, ranging from Kendall to Lauderhill (all open until 6 a.m. on the weekends). Plans are in the works to expand into other neighborhoods, and possibly other parts of the country.

The menu is also expanding, as customers are encouraged to offer up recipes or suggestions for new products. Many of the most popular items -- including potatoes imported from Colombia -- are the result of customer feedback, Lozano said.

``I think that's another secret: Do what people want and it's very easy to make people happy,'' he said.

The house party was a bust after the cops split it up -- something about ``too much noise,'' grumbled Anthony Rodriguez, 19. Now he and his friends were thinking of where to cap off their Saturday night before it completely fizzled.

South Beach? No, they were all under 21.

Downtown Miami? Maybe another night.

A hot dog joint tucked in an otherwise obscure Kendall strip mall? Bingo.

``It's like a mini-club,'' Rodriguez said, conversing with two girlfriends as he waited on his order at Los Perros.

Part fast-food restaurant, part nightclub, Los Perros -- a chain of seven restaurants started by Colombian immigrants -- has developed a loyal following among young Hispanics looking for an after-hours spot to sober up.

``If you go to Denny's it's boring; all you do is sit there and eat,'' Rodriguez said, speaking over the techno music pulsing over the speaker system.

Customers come for ``the dogs'' -- as the name of the store translates to -- but end up staying until the wee hours eating $3.55 hot dogs in a venue that looks more like a South Beach lounge than a fast-food nook.

Flat-screen TVs panel the walls, chandeliers and disco balls hang from above and patrons unwind on plush red couches with beaded pillows or sleek metal furniture.

Some nights, Los Perros' owners will bring in a disc jockey to liven up the party-hungry (or just down-right hungry) crowd.

Despite the party atmosphere inside and closing time at 6 a.m. on Saturdays and Sundays, there is no liquor sold.

`` It's better that way; your body needs a break,'' joked Nathan Cifuentes, 26, as he stopped at the Lauderhill location after calling it quits on a Friday night out.

Customers like Cifuentes, of Puerto Rican descent, instead stop by for the Colombian- style hot dog known as the ``Super Perro'' -- loaded with pineapple relish, fried potato sticks, mozzarella cheese, ketchup, mustard and spicy mayonnaise.

Other Colombian treats like arepas (a cheese filled corn cake), salchipapa (sausage bits and french fries), and maicitos (a spicy South American corn chowder) are also dished up.

``The food is great, but it's about the people,'' said Brittney Medina, 20, who was looking to blow off steam from finals week at Florida International University with her classmate Rodriguez.

Catering to a lively crowd is just what Carlos Lozano, 32, had in mind when he and his ex-brother-in-law Hernando Londono first flirted with the idea of opening a hot dog stand in 1999.

Lozano, who was only 18 at the time, had recently arrived from his native Cali. While Miami and Cali had similar vibrant nightlifes, Lozano still could not get rid of his hankering for a hot dog like those sold back home after a long night of ``rumbeando'' or dancing.

``There was already a large Colombian community here and it kept growing. . . . There was an obvious demand for this kind of late night meal,'' Lozano said. ``We didn't want pancakes or pizza; we wanted food that was ours.''

Lozano and Londono purchased a metal hot dog cart, and started hawking the hot dogs Thursday through Sunday nights along Flagler Street and 107th Avenue as partyers made their way out of the night clubs around Sweetwater.

As the line of people waiting for their chance to order a ``perro caliente'' grew larger, the duo was forced to station their cart in the parking lot of a nearby Pep Boys.

They soon outgrew that location, as cars began waiting in the parking lot before the men arrived, looking to place their orders before the club crowds lets out.

``The police pretty much told us if we came back they'd shut us down, so we knew it was time to find a restaurant,'' Lozano said.

By 2001, using the earnings from their tireless nights moonlighting as hot dog vendors, the duo opened their flagship storefront on Bird Road in Kendall.

Within a year they opened a Broward venue in Lauderhill on University Drive, and have since grown to seven locales in Miami Beach, Sunny Isles Beach, Miami Lakes and Fontainebleau. While the restaurant opens at 11 a.m., Lozano said most customers make their way there after 11 p.m.

``We just wanted to be a place where people had a good time. To re-create the good times we felt back home in Colombia,'' he said.

While the store's original fan base were Colombians, their reach has expanded.

When sisters Perla Salazar, 21, and Andrea Salazar, 23, who hail from El Salvador, needed a break from studying for finals at FIU, the choice was to head to the Los Perros in Kendall. Joining them were friends with Cuban, Colombian and Ecuadorean backgrounds.

``It's just a place where you can eat, relax and feel like yourself,'' said Perla Salazar, 21.

The mix of people is what keeps Ramon Gomez-Giraldo, 28, coming back in Lauderhill.

``Some people are ready to call it a night when the party is over,'' Gomez-Giraldo said before sipping on a can of Postobón brand soda imported from Colombia. ``But people like me come here, because the party never stops.''