I do not know the term "back pack".

Are suggesting that all the students' cars contain standard PBP code (one license). To experiment with sonar calibration and steering reaction time relative to changes in car velocity and 'race' course size each student has a set of definitions that can be downloaded via MPLAB or PIC kit 2 programmer?

I have learned how to write data in the EEPROM section to be read whenever I hit the READ button. That's all the interaction I have mastered.

Ken