A $10 million penalty that the Federal Trade Commission is assessing CarShield, a nationwide marketer of vehicle service contracts, is the latest evidence of the agency’s stepped-up scrutiny of business practices in the auto industry.

The settlement, unveiled Friday, alleges that CarShield’s ubiquitous TV ads, which feature Ice-T and other celebrities, overstate what’s covered under the contracts, which can cost as much as $120 per month.