RE front spoilers/air dams.... what type are you using on the Firebirds?

I have been looking at fitting one of these which suggests either screws or mounting brackets ... however discussion on a Camaro site suggests there are two types with one larger/deeper spoiler that should have the braces connected to fenders (centre brace optional), with the smaller/shallow spoiler being mounted using bolts only....

I'm assuming the Classic Industries spoiler is the latter and doesn't need the bracing.... these are made of ABS and 'should' be more tolerant of curb dings.