[EricH]

Originally Posted by CronosPrime1

What exactly will VEX Ultrasonic Range Sensors do? How will they tell me where a hole in the wall is located? ...And does FIRST definitely allow these and other off-kit electronics?

Ultrasonic sensors use high-frequency sound waves and bounce them off of things--think sonar for an example. If you get feedback, you can tell using return time how far away something is. In this case, you could use it to end up at the ramp (drive forward until value is (whatever it returns at the bottom of the ramp.)
FIRST most definitely allows non-kit, Commercial Off-The-Shelf (COTS) sensors. You have a limit of $200 USD per electronic item max.