We report on our experiences in an e-government project for supporting the automatic generation of E-forms for services provided by local governments. The approach requires the integration of both the model-based user interface design (MBUID) and software product line engineering approaches. During the domain engineering activity the commonality and variability of product services is modeled using feature diagrams and the corresponding UI models are defined. To support the automation of e-forms the implemented feature models are on their turn used to generate E-forms automatically to enhance productivity, increase quality and reduce cost of development. We have developed three different approaches for e-form generation in increasing complexity: (1) offline model transformation without interaction (2) model transformation with initial interaction (3) model-transformation with run-time interaction. We discuss the lessons learned and propose a systematic approach for defining model transformations that is based on an interactive paradigm.