FORTUNE — Out of the 15.8 million vehicles General Motors GM has recalled so far this year, the automaker’s family of midsize cars has made the most appearances.

In the 29 separate recall announcements that the U.S. carmaker has issued in 2014, the Chevrolet Malibu, Malibu Maxx, Saturn Aura and Pontiac G6 have the lion’s share of the callback notices — a total of almost 2.4 million cars, according to The Wall Street Journal. Models of those cars built between 2004 and 2012 had faulty electrical controllers and were called back by GM in May.

While the Cobalt –a compact that became notorious for its defective ignition switches that played a part in at least 13 deaths — will stand out as the most egregious recall due to the fatal safety issues, the Malibu group of midsize sedans affected the most number of consumers, topping the Cobalt and similar models by about 200,000.

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GM is making an effort to more quickly address emerging safety issues, adding 35 product investigators since the beginning of this year. Executives said they consider customer complaints above warranty data when analyzing safety concerns. As a result, recalls are being triggered sooner than in years past, and the company expects more recalls to come throughout the summer.

The rush of recalls hasn’t taken a toll on GM’s sales to date. New-car sales are down 2.3% year-over-year for the first four months of 2014, which has also been a trend for rival automakers Ford, Toyota and Honda.