Maybe there is no such issue in US market at this moment, but at least 6 incidents were reported and verified in China region.
The most serious issue happened on a Chinese customer who bought the brand new Maserati Quattroporte (with the 3.0T engine) back in November, 2013. As of the incident, the car only has around 3,900 miles on it.
On 04/27/2014, that unfortunate Chinese owner drove the Quattroporte in rain for around 3 hours. Then next day the car completely died: it cannot be started and even the door cannot be opened too.
After inspection, Maserati mechanic found tons of water inside of the spare wheel area in the trunk. There are so much water that according to the car owner, fish can even swim in it. You can look at the below live photo to see the ponded water.
The Quattroporte owner is so upset that he put his car in front of the Maserati dealership, and hung a large banner to express his dissatisfaction with Maserati.
The reason why water can go into the trunk, is because the rear wheel well is not properly sealed in the Quattroporte, and water splashed out by the rear wheel can find its way into the trunk and settled in the spare wheel area. Because Maserati put electronic devices such as the battery and lots of circuit board, wires in the trunk, the electric system is totally messed up by the water.
If the electric system failed during driving, according to Maserati, the Quattroporte’s engine will be shut down, and you may loose the steering and braking power, which is an extremely dangerous situation.
Currently Maserati China admitted this issue and asked all customer in China to contact their dealership for inspection and fix. We are not sure whether the Quattroporte sold in other markets has this same issue or not. But if you own a Quattroporte and has experienced strange electric system behaviors, you may want to check your trunk for signs of water damages.