A method 500 and an assembly 200 for determining the presence of gaps located between a first portion 240 of a partially assembled apparatus 228 and a second portion 230. The existence and size of the gap may be discerned by use of a wireless gap sensor 309 which is engaged by the portion 230 as it abuts or comes into close proximity with the portion 240. Other methods 400 and 500 may be respectively used to respectively discern the existence and the size of a gap within an assembled vehicle and to measure the deflection of a portion of an apparatus, such as a vehicle.