If I remember correctly, the scrap should be on the ground next to the northern door of the toilets building.
If it's not there, then I don't know what to tell you (they can be a little hard to see sometimes)
Maybe you got the scrap and your rockstar page hasn't update... try saving your game and then checking again, or look at the in game stats for scraps collected...
[spoiler=uniquecode]This is how you use spoilers![/spoiler]
Last edited by SpinelesS; 11-09-2013 at 05:26 AM.