It is said that once Rudolf Uhlenhaut, designer, racing enthusiast and a senior executive with Mercedes-Benz was working late in his office when a car zoomed down leaving quite a noise behind. He decided to investigate when he discovered that his work colleague Erich Waxenberger was testing his newly developed car.

Mercedes-Benz engineer Erich Waxenberger tinkered by having the powerful 6.3 litre V8 M100 engine of a Mercedes 600 Pullman Limousine and placing it under the bonnet of the Mercedes-Benz W109 that was a smaller car. What emerged was a very powerful model that could seat 5 adults and yet get driven at 200 km/hr. It was labelled Mercedes-Benz 300 SEL 6.3 - W109.

This resin model which is one of the only 408 pieces created is a replica of the one that was used by the Pontiff i.e. with closed roof. Though this model did not have air-conditioning, Pope John Paul II preferred this limousine to the other car he had in his fleet i.e. Mercedes-Benz 600.