I've only had my 07 TL Type-S for a week now and noticed that the chrome trims on the trunk has discolored spots. Is this normal? Does anyone know how to fix this?

 

If you live anywhere that they use mag-chloride to de-ice the roads in the winter, that could be the cause. I'm in Colorado, and have the same problem.
The recommendation I got from the dealer was to clean it with a mild silver polish, and then put a couple light coats of wax on it to protect it.
Looking for a more permanent fix to the problem myself. Leaning towards having all the chrome trim hit with a couple coats of a low-gloss clear, not sure how well that will work though.

 

Update: I couldn't find any silver polish. Ended up using Mother's Plastic Polish on it and it did the trick. Looks good as new now.

 

Don't forget to put a couple of light coats of wax on those chrome parts...that should help prevent them from becoming discolored again. It's not a permanent fix, and it can be a pain, but it's definitely better than having all the chrome discolor.