No, discount will aplly only through a special link that corresponds to the category of your Visa card:
Visa Gold: WWW.SIXT.COM/VISAGOLDCEMEA
Visa Platinum and Visa Platinum Business: WWW.SIXT.COM/VISAPLATINUMCEMEA
Visa Signature and Visa Signature Business: WWW.SIXT.COM/VISASIGNATURECEMEA
Visa Infinite: WWW.SIXT.COM/VISAINFINITECEMEA