The Opel Signum is based on the Vectra and has a lot in common - the whole front, the instrument panel, the front seats, the engines and so on. The main difference is the rear part, which makes the car look like a station wagon or even a larger class car. Namely, Opel sought to give this car the impression of luxury (it costs more than the Vectra, but less than the Audi A6). In part, this car replaced the discontinued larger Opel Omega model. The Signum has a longer wheelbase and length than the Vectra, so it is very spacious inside. The rear seats are not designed to be continuous, but two separate ones with the possibility of an uncomfortable middle seat for a third passenger. These seats can be adjusted in various directions, which is what Opel really does.