A 90* adapter sounds like a great idea for greasing the center spindle.  
By the way, I broke the plastic oil drain plug on my very first oil change.   (Didn't turn it far enough or pulled too hard.)  Rather than make a trip to the dealer I replaced it with a 3/8 pipe nipple, elbow, and plug.  It works well.  I probably won't bother to replace the broken plastic plug.