Factory JBL CD Problems / Metra JBL Harness Sound Quality

[chrono807]

Hi everyone... I had a whole post typed up explaining my situation, and my internet is terrible, so this is heavily shortened. It's probably better that way.

My factory JBL CD player usually reads CDs just fine, but sometimes they sound scratchy. This happens frequently with CD-Rs, infrequently with original CDs but it does happen. Occasionally it won't read CD-Rs entirely. I don't know if that happens with original CDs because most of my CDs are burned. Any thoughts?

Has anyone used the Metra harness that allows you to connect an aftermarket head unit to the JBL amp? How does it sound?

Obviously our factory JBL systems have a little bit of kick to them (compared to anything else I've owned anyway). I love the bass response, I love how the highs aren't muffled, I just love the way the factory stereo sounds.

With the factory integration harness, is it going to sound exactly the same, or will it depend on the deck?

Will the deck need to have a high-pass filter, or does the JBL amp already have one tuned to the proper frequency?

If the deck needs to have an HPF, what frequency would it need to be set to in order to preserve the factory sound?

Any recommended brands? The dealer told me the factory JBL-branded radio is manufactured by Fujitsu-ten, so does that mean an Eclipse deck would provide a better integration than, say, a Pioneer?

I'll start with those... I'll admit that I'm completely anal about keeping everything sounding the way it did when I bought it, so I might have other questions after.

Thanks in advance!