Gas systems are immensely popular as their are still very attractive from the financial point of view. The present fifth-generation gas systems can be applied in modern direct injection engines. Before you have a gas system fitted in your car, have the engine checked, especially the valves, the electrical system, the lambda sensors and the catalysts. After you have a gas system installed on your car you have 30 days to apply to the Motor Vehicles Department for an appropriate entry into your car registration book confirming that your car is equipped with a gas system. To do this, you need a extract from the type approval certificate, a validation document for the system and a receipt for its installation.