This doesn't surprise me. The '06 was originally supposed to be available with TPM. My early version was supposed to be upgradable. I went to the very top of BMW Motorrad Canada to complain that they were failing to meet their obligations of not supplying an upgrade. They countered that sure I could upgrade, but I'd have to buy "new-style" wheels (something different in the internal casting) pricing the whole proposition into the stratosphere. Needless to say, I don't have TPM. Your HID scenario may play out the same. I've seen it discussed elsewhere that the only difference between the two headlight assemblies is the "xenon" stamp in the upper right hand corner. Personally, I find that very hard to believe. To have a separate part for this alone would be hellish on production costs. There has to be some other significant difference.
I do wish you luck, but I really don't think you're likely to have any.
IBA, MOA, ONS
The mind knows no speed limit.
'06 GT - CGM "Katie"
'84 Airhead "Rita"