Wireless networks in vehicles have the possibility to reduce wiring costs and weight, and allow for more flexible installation of electronic systems. However the radio propagation environment inside vehicles such as aircraft presents unique challenges to the operation of wireless networks. An airframe or other vehicle body can be considered a set of coupled cavities. The cavities present a potentially high-Q reverberant behaviour which results in large delay spreads which can cause poor performance in digital radio systems. The presences of multiple, coupled cavities exacerbate the problem. Coupling between cavities is not controlled in vehicle designs and must be considered if radio connectivity is to be ensured. This paper will describe research being earned out at the Universities of York and Nottingham in measuring and modelling the performance of wireless networks in reverberant environments using the Zigbee system as an example.