I also have just noticed a little door rot about a quarter of the way down the bottom of my door. It is identical on the other door also. I was planning on grinding it out before it gets to bad. I will have to refill the material i take out with some bondo . Then i will just use a little touch up paint and then a lacquar clear coat. If you can't do it yourself it is worth the money to have done before it spreads to the rest of the door.