I have a 2004.5 Volvo S40. I've only had it for a year, and I live in California where we don't get any rain for most of the year. However, we just had our first rainstorm of the season, and the floorboard on the driver's side was completely soaked. However, I couldn't find anyplace where the water had actually come in....everything else was dry.

This happened once last winter, but never again. And since it hasn't rained since spring, I kinda forgot about it. but now I'm worried, since it happened already on the first rain of the year. Any thoughts on where all this water is coming from?

Thanks!!