Dear Car Talk:

I recently had to put my older convertible into service during an extended rainy period when my regular car started acting up. The convertible top is original, with no tears, but it didn't hold up well against the heavy rains, and water came into the interior. It got to the point where I started to experience some weird electronic problems. Sounds were coming from my audio system even when the system was off. I immediately stopped using the car, pulled the battery cable and then covered the car with plastic, and left the windows cracked open. The rain kept coming for days after that. Well, the rains have stopped for now, and I no longer hear the sounds, but I have what appears to be mold inside the car. How screwed am I? Would a professional interior detailing, if the detailer was given the facts, do the trick? Thanks.

-- John

Sounds like you bought one of my brother's old cars. He used to have to shovel snow out of his convertibles in the winter.

Even though there are no visible tears in your convertible top, it's no good anymore. You're probably saying, "Duh!" about now.

But people don't realize that old tops shrink over time and the rubber weatherstripping dries out. The cloth top itself even can become porous, and you'll see drops of water seeping through.

So, if you're really invested in this convertible, you need a new top. And you may be surprised to find that it's going to cost you a couple thousand bucks! But at least that'll stop things from getting worse, which is always the first step in dealing with water damage.

I suppose if you're not committed to this convertible for the long haul, the cheaper solution is to just get a car cover and never drive it in the rain. In fact, to remove any temptation to drive it on a day when it might rain, you might want to just remove the top entirely. Or put in a bad set of plug wires, so it won't start in damp weather.

Then you've got to deal with the mold. We're not experts on mold remediation. When a customer drives into the shop with a mold problem, all of my guys barricade themselves in the men's room.

But the first thing you have to do is dry everything out. The sun is your best friend here. Start by removing the carpeting (this will require removing at least the front seats).

Underneath the carpet is a cheap padding that's called the jute. You probably want to just throw that away and replace it.

Then park the car out in the sun for a few days, and lay out the carpeting and seats next to it. Once everything is really dry, you can treat the carpet and seats with a biocide product that's designed to remove mold from fabric.

Of course, you want to test an area first so you don't end up with white carpeting -- not the most practical choice for the floor of a car.

If that treatment is unsuccessful, you may have to replace the carpeting and the seats. Or get the seats reupholstered. Or you could do what my brother used to do, and just drive around in a biohazard suit. Good luck, John.