Is it possible for companies to suppress negative feedback about their companies. The reason I ask is that I have been working at a car finance company and cannot believe the amount of complaints and disputes they receive yet if I google them I can't find any websites or forums that air their complaints
Of course they can, and do, remove unsuitable feedback. Even here on AB you'll see occasional complaints that someone's question or answer has been removed.
i work for a company where someone actually set up a web site for staff to air there views & grievances, within a few weeks it was taken down not sure how but it was.