A recent wave of auto recalls may lead to even more flaws being discovered this year as drivers become alert to design faults, the top U.S. car safety official said Tuesday.

Recalls of air bags and ignition switches last year contributed to an increase in the number of consumers with car safety concerns, said Mark Rosekind, head of the National Highway Traffic Safety Administration (NHTSA).

While the auto safety agency may get about 45,000 consumer complaints a year, Rosekind estimated there were about 75,000 in 2014.