Water intrusion into the trunk is the primary issue across 11 complaints on the 2015 Impala. Owners describe standing water in the spare tire well (4–6 inches in one case), water filling the wheel well, and persistent leaks around the taillight housing. One owner had the taillight gasket replaced, discovered a 2-inch split weld behind the bumper preventing proper seal, and still experienced leaks. Repairs attempted at dealerships failed—one owner reported water continued entering from a different location after two service attempts.
A front passenger floor mat area shows recurring water pooling that dries and returns. Paint defects appear in one complaint describing imprinting from light contact, suggesting compromised clear coat.
Two catastrophic failures—sunroof explosion outward during highway driving and spontaneous fire with only a StabiliTrak warning—appear unrelated to the water issues but represent serious safety events. Dealerships declined repair without charges for diagnosis or have no recall to offer. Chevrolet referred multiple owners to NHTSA without resolving the water leak root cause.
Failure modes owners describe
Trunk water leaks
Water entering the trunk compartment, including the spare tire well and wheel well areas. Owners report leaks persisting even after dealer repairs, with one owner noting a 2-inch split weld behind the bumper preventing proper taillight and trunk seal. One complaint involved water entering from the driver's side rear taillight housing.
When: 57,000 to 100,000 miles; some after extended rain exposure
Symptoms owners cite: Dampness and standing water in trunk; 4 to 6 inches of water accumulation in spare tire well; Water filling wheel well; Persistent leaks after repair attempts; Fungus growth and odor from moisture
Repairs/costs cited: One owner had taillight gasket replaced outside of warranty; another instructed to seek body shop repair due to split weld behind bumper; repairs attempted at dealership but water continues to enter from different locations
Recalls/TSBs owners mention: No recall issued; manufacturer referred owners to NHTSA
Front passenger floor water leak
Water pooling under the front passenger floor mat, recurring even after drying.
Symptoms owners cite: Constant water puddle under passenger side floor mat; Recurring puddle after drying
Paint and clear coat defect
Paint holds visible imprints from objects touching the vehicle surface, suggesting compromised clear coat or defective paint application.
Symptoms owners cite: Paint imprinting from light contact; Possible faulty clear coat
Sunroof explosion
Sunroof glass shattered and exploded outward while vehicle was in highway motion, with no identifiable cause or debris impact.
When: Highway driving speed
Symptoms owners cite: Loud boom sound; Sunroof glass shattered outward; No glass debris in vehicle interior
Spontaneous vehicle fire
Vehicle caught fire while in motion on interstate highway. Only warning was StabiliTrak service message appearing as fire was already burning. No recent repairs or known cause identified.
When: Highway driving
Symptoms owners cite: Spontaneous fire during motion; StabiliTrak service warning message
Synthesized from 11 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.