I have played Lego Star Wars 2 to completion (including max money). While I have played, I have found a few interesting glitches.
Drive a car with a droid:
You can drive a car with a droid,you must not be playing in story mode so you can pick your character. Make a car and get in it with a regular character and drive off a ledge while in the car, when your character jumps out, switch to the droid of your choosing, fall to your death, and when you respawn you will be inside the car driving with the droid.
You don't need to finish it:
After you get all the golden bricks and you get the money fountain, when you build it you don't even need to put the last on and it will still start giving you money.
Fast walking with the droideka:
You can walk fast with a droideka with your shields up (at least until you shoot again). This extends off of the first glitch. Get in a car and switch to the droideka, when you respawn in the car as it, drive off the cliff again, but this time instead of falling to your death, when you abandon the car, land back on the ground. You will be able to walk faster than normally and still have your shields up.