DICE works on my '99
Before I ordered a DICE for my '99 I read a lot of responses from folks that had problems getting the unit to work. The DICE compatibility guide even says it is only compatible for '00 and up models but I decided to try it myself anyway since the DICE had a 30 day money back guarantee. I also exchanged emails with Jessie who told me that it should work since I had the 3 and 6 pin connectors. He thought the only reason the DICE was not advertised for working with the '99 is because not all '99's were prewired for the 6 disc CD changer.
I received the DICE Friday -- hooked it up IAW the instructions (to include the dip switches for single line display (late model)), turned the radio on and viola - my iPod Touch 2G was playing through the stereo. Kewl! Changing playlists, artists, songs, etc... took a little of figuring out since you have to use the seek button to toggle through menus but after I got it, I have to say I really like it.
My next step it to run the wiring back up to the front so I don't have to keep the iPod in the saddlebag.
'06 BMW R1200GS
'99 BMW K1200LT