We bought a 2018 Nissan Versa Sedan that recently flooded with water inside on the passenger's side. We discovered it when my wife got in and put her feet into a puddle on the floor of the passenger's side. She had noticed a sloshing water sound while driving in the months prior, but couldn't tell where it was coming from. We took it in to the Nissan dealer, and they told us it was all our fault and charged us almost 600 USD to clean it up. They put on some good theater about how they'd never heard of such a thing and we were to blame for water leaking into the inside of the car.
Turns out that there are some serious design flaws on the Versa which allow water to collect below the windshield and, when the collected water doesn't drain, it flows into the car on the front passenger side floor. There is a water trough under the windshield wipers that runs from one side of the car to the other. Much like a gutter, it collects water and has two very small drains on each side. When the drains get plugged, like drains inevitably do, water collects in the trough/gutter and will slosh back and forth. There is an entry hole--for cables--about the size of a large book above the trough that then lets the built up water flow right into the passenger side floor. Especially when you are driving and take a turn, the water will slosh up through the hole and into the front of the car. There's a thick pad under the floor carpet that will soak up some water, but after awhile it becomes noticeable. The health danger is that the water has nowhere to go inside the car and will get musty and moldy.
I asked the Nissan dealer--Power Nissan of Salem--how water could possibly end up getting inside the car, and how that could possibly be our fault. Why was there a place where water could collect in the engine area, a drain that could clog, and a hole where water could easily get inside? The manager was very evasive, unwilling to admit anything, and adamant it was our fault. We apparently let leaves fall on the car, which turned into debris that clogged the two drains, which led to the flooding. The manager and others in the shop were all frowning at us for allowing this to happen--they insisted it was clearly our fault for parking the car outside, in the rain, near a tree where leaves could blow on top of the car. We paid almost $600 just to get our car back and left terribly frustrated. The problem looks like it will recur considering that the drains are bound to get plugged up again. It's probably just a matter of time, since it rains a lot in Salem, Oregon.
Long story short: Nissan allowed a serious design flaw in the 2018 Versa Sedan that leads to flooding and wet floorboards. There should not be a place for water to collect, nor a drain that is prone to clogging, nor a hole for water to flow inside the car. One guy captured this whole story well on Youtube (see Nissan Versa Passenger Water Leak by Tony Sinatra, Jan 26, 2019, ). Part of the problem is you have to remove the windshield wipers and plastic covering in order to see where the water collects, otherwise you will see nothing and be left wondering where the water is sloshing around and getting in.
Had I known of this design flaw and the problems it would lead to, I would never have bought the car. It's time for a recall, an engineering design change at Nissan so future cars don't suffer the same leaks, and for dealerships to be honest about the problem. Buyers are not responsible for water leaks inside new cars.