Prius untouched in Garage for 1 year. Wet inside!

Sounds like you have a leak somewhere and the car had the water in it before you parked it. Older Gen2 Prius have known problems with leaks, but less so with Gen3... Regardless, I'm sure getting the car detailed will solve it all and then you need to find out where the leak is.

 

check the 12v, spare tire and hybrid batteries. leaks are usually cracks in the rain gutter under the plastic molding

 

Do you mean the rain gutter around his garage?

 

rear side flaps between upholstery and chassis probably stuck open.

 

Probably already had a puddle in the back that wasn't noticed during frequent usage.

 

Good check-list item when mothballing a car: take everything out in back and check/clean.

 

Well....
I'm a hard sell on the Ford being better built, and unless your garage has a leak, you brought the water and the Prius into the garage at the same time.
It could be anything from a batch of bad hatch seals (second post this week about leaks) to your car having been previously wrecked, to a hatch-seal deformation caused by closing it on something sticking out of the hatch.

We get 60-70 inches of rain during an average year where I live, so hatch leaks do not go long undetected.
I haven't seen or heard much in the way of hatch leaks for our 2010 G3's and we probably have a half dozen scattered around locally.

So...
Time to sell the Prius (an up optioned Pip if your siggie is correct) and drive the Ford for a while until the car market cools down somewhat, IMHO. I would also make full disclosure on the condition of the Pip and price-adjust accordingly, but the moldy interior will inform any potential buyer of the car's condition.

If you're still in LA, and you have two cars that you parked for a full year then it might be time to re-assess your transportation needs.
Since you obviously have a garage that you're not sub-letting when the used car market cools down you might be one of those rare people whose needs can be met with a used BEV or maybe another PHEV..

Good Luck!

 

Just editorial: maybe hatch “ponding” is more succinct?

 

Owner of a Ford Escape and previous owner of a PiP. My guess? Just a complete and random guess here:

The Prius like most Japanese cars allows the HVAC to be off with vents open. I seem to recall the vents automatically go to refresh after a set period on their own if you use auto climate control. Curiously, the Ford Escape and most domestic vehicles I've driven completely close the vents/goes to recirculate if you turn off the HVAC.

So my wild guess is that the Escape vents were closed and the Prius vents were open when you mothballed the vehicles last year. With the 100% humidity where I lived, moisture could easily build up inside in the garage. I have to run a dehumidifier in the basement/walk-in garage during summer or I find puddles everywhere. The moisture more easily makes it way inside the Prius than the Escape.

 

water in the spare tire area evaporated and helped mold get started.

detail it and it's fine

 

no, the molding alongside the roof edge of the car

 

I've read, with any mothballed car, you want to leave one window slightly down, maybe with rags loosely stuffed in the gap, to prevent insect incursions. And a small tub of silica gel (or salt?) is good.

Also, regarding AC: if you've been running the AC right up to shut-down, there's invariably moisture in the system, just like a glass of ice water on a hot day. Before mothballing at least, try to run the vent system a good length of time with AC off, give the humidity a chance to disperse. This is actually good practice all the time.

 

Make sure your AC drain line is not disconnected which can cause hard to notice pooling under the carpet.

In any case it should be relatively easy to take out the seats and carpet and clean or replace them. Based on my years of doing PH mold investigations -- if upholstery is visibly moldy you should replace. If its only a musty odor you can clean instead of replace if you don't have mold allergies. Still need to figure out the moisture source so this problem is not repeated.

SM-G960U ?

 

In my normal winter use, in a different climate zone, there is generally excess moisture already inside the car, from human respiration, wet clothing and footwear, defroster/AC systems, etc. So to avoid condensation and frost on the insides of the windows, it is important to let moisture escape. That is why I get better results with vents left open instead of closed.