Context: Software testing is a crucial area in software development. It has been found that there is little evidence on how testing is performed in software automotive domain. Challenges in this domain have not yet been fully evaluated. Furthermore, interactions between test procedures, and other activities of software development are left unexposed. Assessment of test process is an important part of improvement initiatives. Objectives: In this study we perform an in-depth investigation to identify challenges which lead to wastes in test process in the context of automotive software domain. To this end, we also identified strengths that add value in test process. Methods: We performed a Case study at a Sweden based large automotive organization. To this end, we conducted semi-structured interviews and used Grounded Theory method for interview data analysis. We used Value Stream Mapping (VSM), a Lean methodology tool for test process assessment. Furthermore, we conducted Systematic Literature Reviews to look for evidence of similar problems and solutions offered in peer-reviewed literature. Results: We grouped the identified challenges and strengths into 10 and 4 categories respectively. We also identified 7 kinds of waste and 4 kinds of values based using VSM. Based on systematic literature reviews, we proposed 7 solution proposals, an agile process model with practices. Conclusions: We conclude that VSM is an efficient tool in eliciting improvement potentials in software testing context using qualitative data. In regard to solution proposals, we propose further empirical work to evaluate the solution proposals themselves and tailor to company needs. However, the results obtained through this study can be compared to test processes at other companies in automotive domain.