crouch on a ramp, then jump, if there are bricks close enough above you, you will go through them.
you can go through things if you hit them a the right angle in a vehicle
water emitter problem, (pic and log coming soon) EDIT: Pic is here, log doesn't matter because I can reproduce the bug on any computer by jumping off of a vehicle while underwater, and if it goes up to the top like the magic carpet does, if you jump on the vehicle just when you see the splash when it hits the surface of the water, you are able to drive the vehicle out of the water and still have the water emitter. YOU NEED TO CATCH THE VEHICLE AT THE EXACT TIME AS SOON AS IT EXITS THE WATER!