1. I took out the VANOS solenoids and "cleaned" them via blowing compressed air into the holes and around. Wiped down cleanly with a shop towel (blue).
2. Swapped the Intake and Exhaust solenoids as recommended for troubleshooting reason. e.g., see if the code scan shows a switch in position. My code P1553 which is BMW FC 2A99 seems to indicate an exhaust VANOS solenoid issue.
3. I fired up the car right after the swap and viola, NO check engine light!
4. I did an OBD-II scan again, but it still shows the same trouble P-code of P1553. I could not clear it. My guess, it may require a "special" BMW code scanner to clean it? not sure. Good news is, there was no new code. e.g., IF I got P1554 which will indicate that the bad VANOS solenoid was indeed the case indicating now an intake solenoid issue.
5. Since Friday night, I have driven about 250km+ ... so far so good. Fingers crossed.
Since the CEL did not come back on immediately after I cleaned the VANOS solenoid, I am quite confident they are related. So, if it does come back on, I will most likely just buy new ones to replace it...