Here are some pictures of two different centre brackets, showing some variation in shape and fitting location.
Bracket No 2 Upper, Barcket No 1 lower
Bracket No2 in the best position for No1. Note that the pads do not sit in contact with the roof.
Bracket No2 shown in its best location. This is about where the fitting instructions say to mount it.
Bracket No1 in its best location.
Bracket No1 in the 'official' location. Again, note how the mounting pads are not sitting on the roof.
Here the two brackets, individually.
Bracket No 1.
Bracket No 2.
Cheers
Brett