Physical sensors are an important part of control systems, especially vehicular control systems. Sensor readings help drivers to control their vehicles as well as their internal systems while keeping a vehicle stable and running. Currently, a modern luxury car carries hundreds of diverse and precise sensors and not all of them are visible to the driver. However, there are phenomena and aspects for which there are no physical sensors available. Virtual sensors combine readings from multiple sensors in order to develop their own output values based on conditions and models, and, eventually, substitute and monitor failing physical sensors, as well as sense complex variables. Designing a virtual sensor is usually a difficult process due to the complexity of the different processing stages it comprises. This work studies the process of creating and prototyping vehicular virtual sensors, describing the development stages and presenting examples of virtual sensors created with a framework developed to facilitate the design process.