Make a MovieClip dissapear from the stage

Hello Adobe Community

I am teaching a high school Game Design class and am a total novice with ActionScript code but very familiar with creating graphics and animating them. I need help tweaking a program so that a MovieClip object will disappear when contact is made with another movie clip. 

The game is a racing game and I want to have the "Car" seemingly pick up objects along the track as it completes the course. 

In the Library I have a MovieClip linked as 'Track' that has several layers, a road, finish line, road hazzards and points that the player must pass to stop the timer.  I want to add objects that the player collects and have them removed from the display stack or just have their alpha changed to zero when the car passes them. 

I would imaging I have to add the objects to an Array and then write a function to change their alpha but I have tried a few things and being a total newbie nothing has worked so far. 

I would be eternally grateful for some help or even direction on where I could find training writing this function. 

I have uploaded the existing code for the game, the new Movie Clip object I have called Egg in the library and linked as a class. The vehicle has a instance name car and is in the Track symbol with an instance name gamesprite.

I'm sure what I want to do is possible but currently not within my capabilities. 

Thank you so much for your time if you decide to assist in this matter.