What I have found effective on my '97 GT is rather simple. I use turtlewax chrome cleaner (found some at walmart last time). I've used mother's too but I prefer the cheapo turtlewax stuff, it's simply stronger. Cleaning is just a matter of using it with a brush and putting in the elbow grease.
I've been doing this a couple times a year on my car since I got it new and when I am done each time the pipes look like new. I think I've used polishing compound on occasion too (no chrome cleaner on hand) and it worked well too.