I have an 09 Fit sport and I have had a lot of issues with water getting into my car as many other fit owners have. I have made quite a few repairs and modifications trying to prevent water in my rear wheel well and rear carpets for three years now. And after making repairs to all the common leak problems, I couldn't find where water was still making it in until today. After repairing a leak from the antenna in the roof two years ago and a leak from the rear door moisture barriers failing last year, I once again ended up with water in my spare wheel well.

After some investigating I found dried white water trails behind the left side tail light access. I thought it may have been coming in from the tail light gasket, so I took the tail light off. Instead, I found 4 very small holes in the weld along where the tail light sits. It doesn't look like the weld has cracked in any way, it just looks like some bad welding allowing water to slowly drip through. I just used my finger to spread some silicone over all of the holes to seal them. In the same area, I could also see dried water marks coming from a screw that is screwed in from the exterior holding the rear bumper on. I didn't want to just glob the screw with any sealant in case I need to remove it at some point, so my solution was to silicone a cap over it to prevent the water from making it into the car. Before fixing it I wanted to be sure this is where water was getting in, so I poured water over the holes to see if it was making it through and following the water trails I found. Sure enough it was running down the sheet metal into the wheel well.






I have seen other threads talking about welds cracking near the top of the trunk hatch, but I have never seen anyone with this experience. I thought I would share in case someone else is still dealing with water after fixing the various other leaks.

 

Thanks a ton for this information
Good stuff to keep in mind for sure!