Have a 2012 plug in prius. Think that first year was only a base type model. Several months ago I replaced the 12 volt battery, and discovered the back right corner where the battery located had a water puddle up to the battery. I got a turkey baster and drained the area when I replaced the 12 volt battery. I checked today and there was about a half inch of water. I see no evidence of leaking anywhere. Do not know where it is coming from. Is there any drain there? I park it outside. Anyone else seen this? It has been a very wet year in the southeast. Posted via the PriusChat mobile app.
Sorry, I should of searched the forums before posting. There is plenty of information about this and leaks at taillight, welds ect. I will check those areas. Posted via the PriusChat mobile app.
One possiblity is cracks in the seals in the grooves running the longitudinal length of the roof, the ones with black rubber runners. You can pull the runners out easily (just learned this recently myself), check there. I'd clean it thoroughly for starters.
Not sure if it's a problem on these, but I've seen on other Toyotas of this era the seals around the air vents inside the bumpers can fail, letting rainwater into the rear of the car. Seals on the rear light clusters are a common issue on many cars.
