Formal modelling and verification of variability concepts in product families has been the subject of extensive study in the literature on Software Product Lines. In recent years, we have laid the basis for the use of modal specifications and branching-time temporal logics for the specification and analysis of behavioural variability in product family definitions. A critical point in this formalization is the lack of a possibility to model an adequate representation of the data that may need to be described when considering real systems. To this aim, we now extend the modelling and verification environment that we have developed for specifications interpreted over Modal Transition Systems, by adding the possibility to include data in the specifications. In concert with this, we also extend the variability-specific modal logic and the associated special-purpose model checker VMC. As a result, it offers the possibility to efficiently verify formulas over possibly infinite-state systems by using the on-the-fly bounded model-checking algorithms implemented in the model checker.