Rect.Contains in front of gameObject

Hello, i'm developing my first game, and i face this problem:

i'm using Rect.Contains to check if my touch hitted the texture that i draw on OnGUI, but, whenever this area is "in front of any gameObject (cube)" the touch is not detected, could not find anything related to my doubt, so i came here...

is there something i can do to my Rect.Contains detect my touch even if the rect is in front of any gameObject?

if that explanation was enough, i hope someone could help me :)

THX