I wish that Rockstar would..
1) Make the forklifts work as in San Andreas - it was cool to flip cars over and trying to crush things.
2) Make the Packer truck work so I can crush cars inside of it untill it all explodes..
3) In San Andreas one of my favorite activities was to get a Bagage Handler (airport tug) and connect it with a whole lot of those bagagecarts - creating a mini road-train. In GTA4 the tug and carts also appears (as well as those airplane access-stairs which were fun to attach too), but they are unable to connect to each other... and that's a shame!!
4) In TLAD we are introduced to the good old Tow Truck.. LET IT DO WHAT IT IS SUPPOSED TO DO, so I can kidnap a police car with officers and make it hang from the edge of a cliff.