When I purchased my 2008 528xi you were unable to order the High Definition Radio if you wanted to receive live Traffic Information. Antenna Splitter IBOC, PN 65209192725 at RealOEM says it is for vehicles that have both High Definition Radio and Traffic Information. Can I retrofit with this part to allow both options in my vehicle? Coding required?

Not directly answering your question, but I found HD Radio as nice to have, but definitely not worth retrofitting. Although still an improvement over analog, the sound quality is nowhere near MP3 quality, let alone CD quality. You're also subject to audio processing by the radio stations, which they do to accommodate most common radio freq responses.

Another annoying thing about HD Radio is that it frequently switches between HD and conventional, depending on signal strength. There's audible split-second blip/delay everytime this happens.