what would the weight of the exhaust, headers, cats, air box etc from ba xr8 sedan

Good question.

my airbox, factory snorkle type maybe about 2kg
Still have the factory headers in the shed, about 4kg
Cats, hmmm 8kg
exhaust, well hmmm about 20-25kg maybe a bit more.

Why dont you take yours out of your ute and weigh them, you will get a much better idea

a mates needs to know for freight costs. mines got no mufflers in it anymore so it would weigh a bit less and cant be bothered to take it off. Thanks anyway