I was wondering how that rear rack would look on the tail of a Silver AK since it only comes in Black. Pricey little bit of kit that thing is but the only one that looks good on the AK 550, like it belongs, IMO. That would be the only part to prevent me from getting one right away. Saw one on eBay for $388.71 (OK, so I'm cheap). Did your's come with the Matt Silver Crystal tail panel with the slot already cut out or did you cut the slot yourself?
And does that warning stamped in the center of the plate say max load 8kg or 5kg? That means about 30 lbs either way... Right?
Having done electrical work on several bikes including installing isolated fuse blocks and power circuits for farkles and trailer harnesses, that plug is a typical 5 wire tail light system plug. Per the electrical diagram I downloaded for the AK 550 here is the wire color breakout for those who want to know:
Blue wire = Right turn signal
Orange wire = Left turn signal
Green/Yellow wire = Brake light
Black/Green wire = Running light
Green wire = Ground