[Dactrius]

Since no-one ever listens to me, I'll post this stuff again

Complete the shooting course = paper target on table in office
Complete the shooting course with 45 points = trophy on tv in hotel room
Complete Hyman memorial events = trophies on top of tv in mansion
Complete film studio missions = posters of your movies in hotel room
Complete Phils missions = boomshine barrels in hotel room
Complete the bank mission = bag of cash in hotel room (on bed)
10 Hidden packages (I think) = Hidden package (open) in hotel room
Kill Diaz = Random changes to the mansion (First the portraits, then after a while pizza boxes and junk start to appear)

OTHERS (That I'm not sure about)

Gash bags in office (Could be the one where you smash windows in mall)
Gun mags on office desk (Maybe the one where you cap the mexicans but I doubt it)

TIDBITS

Cement boot man = near to your mansion in the water (Don't know exact location)
Sunken Cargo Ship = Central south of map (In sea - obviously)

Appartemnt 3C = Seems not many have found this. At the Southern part of the first Island, sort of North West from the Pole Position club, there is a square appartment block (Shown on the radar as a white square surrounded by a pale green one). On the balcony pointing South there is a black doorway that you can enter. Inside the bedroom is a case of drugs (Serves no purpose) and a chainsaw in the bathroom (Complete with blood all over the walls)

I'll add more as they surface in my memory, so don't wait up!