CLEVELAND -- An exclusive 5 On Your Side investigation is continuing to gain national attention.

Investigator Ron Regan was the first in the country to expose a problem that affects 40,000 cars on the road right now.

The problem involves a significant defect with the Pontiac GTO. Now, the government is taking action and GTO complaints are mounting.

Joe Pinter bought a 2004 Pontiac GTO, but within months he noticed his front tires were rubbing against the inside strut.

It was the same problem that caused a tire to explode on a Cleveland freeway.

"The inside of the tire just had big groove and it was, you could see on the strut where it was actually rubbing the paint and it was rusted in there," Pinter said.

Pinter is just one of scores of GTO owners in 15 states around the country, as far away as California and Puerto Rico, who contacted NewsChannel5 since the investigation first aired last week.

The National Highway Traffic Safety Administration has now opened an official defect investigation in the wake of our report.

Mike Jankovich is another GTO owner who watched our report and called to tell us what mechanics found.

"They showed me that the shoulder was completely gone on the front right tire, almost gone on the left side, OK, then we inspected the two back tires, which had spent some time on the front because we rotate them and they both showed wear as well," he said.

On Web sites, NewsChannel5's report has gained national attention, including e-mails saying, "I couldn't believe how chewed up the tires were," and "Caused severe safety problems."

"I think that we finally got someone on our side that can bring something to light that a normal citizen can't do that," said Jankovich.

"I think it's great. I think it will definitely help out other people because there are a lot of people out there who are spending their own money to fix this problem. There's a ton of them out there and they look at it as something they have to take care of," said Pinter.

A representative for General Motors said that it is cooperating fully with the federal defect investigation and will turn over all of its complaints and warrant claims to the government.

You can file a complaint with the NHTSA at its Web site.

You can also find out more information at the Center For Auto Safety's Web site.