The city of Dallas is seeing a spike in catalytic converter thefts.
Two were reported Wednesday within blocks of one another near Oak Lawn and Maple avenues.
"These people are good at this," Christopher Nichols said.
His son's catalytic converter was stolen in broad daylight outside the U.S. Post Office on Oak Lawn Avenue.
Nichols said his son was only inside the post office for about 15 minutes to mail a package.
"He came out, started his car and 'boom,'" he said. "It sounded like a race car. It scared him to death."
His son's Honda Element was one of several sport utility vehicles targeted in Dallas this week.
The manager of Legacy Tire near Love Field said he has seen a recent spike in his converter business.
"Normally it's been one or two a week, and now it has come up to three or four," Luis Martinez said.
Catalytic converters reduce harmful vehicle emissions. Police say thieves are not interested in the actual part, but what is inside.
"There is precious metal in the catalytic converter that can be resold," Martinez said. "They steal them, take them to scrapyards, and they buy them."
Their victims are stuck buying a new converter, which can cost thousands of dollars.
Martinez said converter thieves favor Hondas and Toyotas -- especially trucks and SUVs because they are higher off the ground.