2005 Dodge Magnum What when you have a remote control key.

If you're referring to the big gray transponder key, it's a sealed unit so water won't hurt it. The engineers figured someone would drop it in a puddle, so they planned for that.

If you have the remote key fob attached to the key, they can be popped open to replace the battery. It's not exactly sealed against water, but it will take quite a while for water to get in. Even if water does get in, it won't hurt anything on the car. I would suggest popping it open to let the water dry out as quickly as possible. If you don't, it will take a very long time for the water to dry out on its own. Corrosion will develop inside, likely making it inoperable.

Caradiodoc