Caterham driver Giedo van der Garde's future father-in-law is reported to be considering buying into the Williams Formula 1 team.Marcel Boekhoorn, a businessman and billionaire, has "serious interest" in taking over Toto Wolff's 15% stake in the UK-based team.FUTURE FATHER-IN-LAWBoekhoorn's long-term girlfriend Denise accepted van der Garde's marriage proposal in 2013.Van der Garde, who is sponsored by the Boekhoorn-linked Dutch fashion label McGregor and managed by its chief, could be looking for a new seat for 2014, amid rumours former driver Heikki Kovalainen is returning to Caterham.Van der Garde's manager Jan Paul ten Hoopen commented: "Marcel would only consider such a step from a responsible business perspective."He confirmed that Boekhoorn and Wolff, now a co-owner and director at Mercedes, had "talked to each other". Asked if the deal would pave the way to Williams for van der Garde, manager Hoopen insisted: "Basically, buying shares and getting a race seat are distinct."While refusing to rule out taking McGregor back to Williams as a sponsor, he added: "Giedo would like to drive for a renowned team, and I think Williams knows what it is doing."Williams already has a Dutch shareholder in the form of the investment firm Cyrte, founded by billionaire John de Mol, who own a 5% stake.