CarComplaints.com Notes: The only area of real concern for 2010 Mazda CX-9 owners is the brake booster.
In 2014, Mazda extended the warranty on the 2007-2013 CX-9 brake booster to 7 years / 90,000 miles. However this extended warranty has expired, so buyer beware.
This Mazda CX-9 brake booster failure isn't terrible in terms of repair cost — it "only" costs $550 average to fix. However it is a safety issue when the brake booster fails as it increases stopping distance. Owners have reported having to stomp on the brake pedal, & crashes/injuries have been reported due to this CX-9 brake booster defect.
Ratings only apply to the model and body or seat type tested. The date of manufacture and optional safety equipment can affect results. For full details see www.iihs.org.