The thread that Arch provided a link to was the one on this forum, and although useful in some respects, requires lots of reading to get all the info. The more complete one, at least as much as could be obtained, on one single post is here.
As new bike sales of the LC4 in the US is semi-nonexistant at this time, I would not blame any maker for discontinuing, or avoiding the LC4 mufflers or systems.
Supertrapp still shows the IDS2 on their website, which is odd because I was told months ago that it was discontinued. They may still have it up as reference, or have changed their minds and decided to continue manufacturing it.
There may be several distributors and dealers that still have them in their inventories.
3 Inch IDS2 Slip-On Quiet Series $ 308.60 611-9600
3 Inch IDS2 Slip-On Racing Series $ 245.02 613-9600
Parts Unlimited still shows the "Race Series" in their '04 Dirt Catalog, and as the quiet cores are "common" and not specific to model, one could get a race core muffler kit and install a quiet core.
Parts Unlimited "04 Dirt Catalog, page 470
3 Inch IDS2 Slip-On Racing Series PU # 613-96002 @ $227.95
Although I use one, I'm not trying to endorse the IDS2. I'm fond of the tuneability feature not available on most other mufflers. There are mufflers and systems that will produce more peak HP and torque than the IDS2, that are lighter and in many cases, look way tricker... after all, it's only money.
But, if someone wanted
a IDS2, I think they could find one with only a little
bit of effort.
I would start by contacting 1.) Supertrapp 2.) on-line parts sellers 3.) your local dealer.