HOUSTON -

In tonight's Restaurant Report Card, we're taking you inside kitchens on the go. They're restaurants on wheels, but we're not just talking the old taco truck.

Today's mobile food units are serving up everything from cupcakes to gourmet lobster rolls. That's what's on the menu, but KPRC Local 2 consumer investigator Amy Davis found some items truck vendors don't want you to see.

Got a craving but no time to sit down at a full-service restaurant? With 871 licensed food trucks in Houston, you're in luck.

You can find everything from cupcakes to cajun food, tacos to gourmet lobster rolls and Vietnamese food, too.

Food truck vendors Davis spoke with said they've got followers -- fans on Facebook and Twitter who log on to find out where their trucks will be parked just to drive over and grab some grub.

"Yeah, social media's the key to the game," said H-Town StrEATS chef Jason Hill.

But it's not just hungry Houstonians following them. Houston health inspectors are, too.

When they boarded Zilla Street Eats back in March, inspectors said they saw "maggots inside of the refrigerator." KPRC Local 2 couldn't reach the owner for comment, but inspectors said Zilla cleaned up the insects and is rolling down Houston streets again.

At Alex's Mexican Grill, inspectors found dead roaches in the steam table. Alex told Davis he's since parked the truck until he can get it re-inspected.

Inspectors said cooks on Bernie's Burger Bus had no potable water to use for cooking and cleaning.

They said the water wasn't hot enough when they stopped by H-Town StrEATS back in May.

"We basically had to shut down operations and wait 5 minutes until the water got up to 115," explained Hill.

It was the same day inspectors popped "Phamily Bites" for having 20 pounds of food on board at improper temperatures.

"This kind of report, it doesn't explain what really happened," owner Van Pham told Davis.

He said inspectors made him toss the food minutes after it was delivered to his truck, even though there was nothing wrong with it.

"I was prepping the food," Pham explained. "I was cutting the meat, marinating it, then I was going to put it back in the fridge."

Inspectors served up a perfect inspection for "MMM Cupcake"... and that makes their customers smile.

"They sell out really quickly," said customer Marlene Albin, who left her downtown office on a cupcake run. "Once you see them, you just got to come and grab your cupcakes."

Food truck vendors have to comply with all the same rules as regular restaurants. Some said that can make it difficult. Try keeping your refrigerated items at 41 degrees when it's 100 degrees outside.

If you want to find some of the trucks in our report and others, check out: Haute Wheels Houston

We hear a Food Truck Festival is in the works for later this month: Haute Wheels Food Truck Festival.