Instead of a purr, the Mercedes-Benz roared as soon as the key turned in the ignition.
When Mark Shumate looked under the car, he noticed the catalytic converter had been cut out. And the next thought that ran through the used car dealer's mind?
The owner of Shumate Sales & Storage on Dale Mabry Highway said thieves have been targeting his business over the past five years, taking at least 50 catalytic converters from cars on his lot and selling the stolen parts for scrap.
"It's horrifying," Shumate said. "There's no safeguard. It's a huge problem."
Although new laws passed this year have made it tougher to resell stolen catalytic converters, the devices continue to rival home air conditioning units as a favorite target for thieves, said Tampa police Officer Dan Hinsz.
The components — which run between the engine and the exhaust and clean up vehicle emissions — can be sold at scrap yards for upwards of $150, Hinsz said. What makes them so valuable are the metals inside them, such as platinum.
What's frustrating for victims is that catalytic converters are required by law, and replacing one is expensive, he said.
"That's the killer part of it," said Hinsz, the lead investigator of metal thefts for the Tampa Police Department. "It costs about $1,500 to get it replaced."
Since July, Hinsz has investigated five cases of catalytic converter thefts, all of them occurring in used car dealerships like Shumate's. A total of 30 converters were stolen in those cases.
Last year, thieves targeted student and faculty lots at Hillsborough County schools while classes were in session.
"During the day, everybody was inside the buildings," Hinsz said.
The frequency of the crime "goes in spurts," Hinsz said. "Two years ago, I had hundreds stolen over a three-month period."
Tougher regulations passed in July have helped lower the number of catalytic converters stolen within city limits this year, he said.
Dealers must now provide documentation of transactions within 24 hours of purchasing items from metal scrappers. People selling scrap metal no longer get paid in cash; instead, dealers now pay by check and the payment must be sent to the address on the sellers' driver's license.
State Rep. Larry Metz, R-Yahala, said he co-sponsored the bill because law enforcement agencies told him they were having difficulties in making arrests in cases of metal theft.
"There was no real paper trail, no real accountability," Metz said. "There was no way to close the case."
Monty Khanna, purchasing manager at the International Core Supply scrap yard in Tampa, said he's wary of metal thieves. When someone tries to sell him a catalytic converter, he asks the person what make, model and year the car is.
If the seller can't answer, there's no sale, he said.
Khanna said the new law has cut his profits from catalytic converters about 50 percent, but he still buys them in bulk because he works with car dealerships across the state.
"Anybody dealing in metal legitimately has no problem," Khanna said. "Legitimate businesses have no trouble complying with the law."
Khanna said he also photographs every catalytic converter he buys and has paperwork for each part. He had about 8,000 converters in his warehouse this week ready to be shipped out.
Extracting the metals is a tedious process that can only be done at refineries with equipment valued at millions of dollars, Khanna said.
Platinum, rhodium and palladium are the three metals used in catalytic converters because they absorb the heat well from the engine and exhaust, Khanna said.
Converters have a honeycomb design, the consistency of lava rocks and are slightly smaller than a brick. The devices are wrapped in tin casings with two pipes protruding from each end.
Thieves using cordless saws can remove catalytic converters in as quick as two minutes, Hinsz said.
People will notice something is wrong with their car as soon as they start the engine.
"It will sound like a drag race," Hinsz said. "It's a roaring sound."
Thieves prefer converters from trucks and SUVs because they sit higher off the ground and are easier to get under. Converters from trucks are also bigger than converters found in coupes and sedans.
"Nissan, Honda and Toyota have higher platinum content," Khanna said.
Hinsz said there's really no way to prevent catalytic converters from being stolen.
The best thing residents and businesses can do is install security cameras on their properties to catch thieves in the act and help police identify suspects, he said.
"Park in places where there are cameras," Hinsz said. "Install cameras. Put up signs showing the area is under surveillance. And make sure the cameras are working."
Shumate said the lack of deterrents is disheartening.
"They're targeting dealerships, repair shops, any business owner with a fleet of vehicles," he said. "That's life in the big city, but this is an epidemic."