How do I create a NumberValue that can be changed and read by scripts in a vehicle seat and player?

I first tried getting the script in the vehicle seat to duplicate a local script and a NumberValue into the playerGUI. The local script would change the NumberValue to 1 when a button was pressed, which worked, and then the script in the vehicle seat would print the value but, it would always print 0 instead of 1. After trying to find solutions, the only one's suggested were to put it in replicated storage however, the problem with this is that this would only work with one vehicle but, not with multiple vehicles with the same script and the same variables in the same place.