The automotive industry is under a deep competitive reorganization process that manifests itself both on the demand and on the supply side. The competitiveness of this reorganization is highly dependent on a flexible production system, able to produce on demand, different vehicles (models) on a single assembly line. Due to demand requirements, production has to adjust faster to new models, each one with a large number of individual feature variants, and complexity grows in production. In addition, lean manufacturing principles introduced Just-in-Sequence as a further key issue of modern automotive production. In order to explore the single line concept related with the Just-in- Sequence principle, Car Sequencing policies avoiding blockage and starvation caused by product variety are needed. The main goal of this project was the development of a mathematical model and a computational tool to define the car sequence in the final assembly line in a daily production run. The car sequence depends on the daily demand, called the production mix, and should avoid line stoppages and minimize the number of workers needed to complete the sequence in the minimum time. This goal was achieved and we have created a new exact approach for Car Sequencing that considers limited capacity, special markets priorities and clustering of colors. An Integer Programming model was developed, but when considering clustering colors it became more complex and hard to solve. To overcome this difficulty a heuristic procedure was presented. Results show that the use of this new heuristic integrated with the exact integer model is a good approach for the Car Sequencing problems. The models were run in the software IBM ILOG 12.2 framework in a Intel® Core™2 Duo CPU T9600 Toshiba laptop @ 2.80GHz with 6 GB of RAM and we obtained good results for the heuristic in less than half an hour, for three hundred cars and seventeen options. As a result of our work we show that the clustering of colors improves the performance of the global manufacturing system and that our tool can be used daily for Car Sequencing in automotive companies.