4.6is Front Spoiler Installation

[teknic]

Has anybody ran into any problems installing this piece on a facelifted X? The rear was a fifteen minutes job. But the front is taking me more than I was expecting to. For starters, I cut all the inner tabs and got some 3M whinshield adhesive in black. Cleaned up the front bumper with watered alcohol, and put a bead of the 3m stuff all around the piece. The upper tabs that supposedly attach to the lower grill insert do not align 100%. I decided to first fit the center of the piece to the car and then go with the rest, but once I have one side attached, the other side comes totally out of place.
I just removed all the adhesive off the bumper and the spoiler to start all over again, but wanted to check here first for any input.
Thanks