Height Adjustment at Striker, A3 and Sportback:

Fig 1: Identifying Rear Height Can Be Adjusted By Sliding End Plate -1-

Courtesy of AUDI OF AMERICA, LLC

-- Lightly tighten the nuts -2- ; the striker -1- must still be adjustable.

-- Close the lid until it is flush with the transitions.

-- Open the lid and tighten the nuts -2- to the tightening specification -Item  : Nut.