I found some 3/8" chrome spacers to get the rack off the passenger's back rest pad top and some wide stainless fender washers to go under that , epoxied the spacers to the rack standoffs. Found out the 4 mounts did not sit completely down on a flat surface , 1 was up ~1/8 " , finally got that one down even with the other 3 - it would have tried to tweak the plastic tail trunk lid cock-eyed from the get-go w/ hole stress.
Now I'm down to deciding if it is better to have the "high tube" of the rack to the front or to the rear ; any recommendations from those that have an E96 ( or E81 ) GIVI rack or similar ?