REUTERS — Don’t trust the driver of a fast car. Porsche drivers are less faithful than any other group of car owners, with almost 50 percent of them cheating on their partners, a survey published in German magazine “Men’s Car” has revealed. Among German men, Porsche drivers were the least faithful, with 49 percent admitting infidelity, followed by BMW drivers at 46 percent. Among women, Audi drivers were the least reliable, 41 percent admitting to affairs. The most faithful group were owners of Opel-Vauxhall cars, with only 31 percent of male and 28 percent of female drivers in Germany having committed adultery. The survey was carried out by Hamburg-based opinion poll institute Gewis, which questioned 2,253 male and female drivers aged 20 to 50. The results follow similar findings from the same magazine showing that male BMW drivers had the most sex.