This is most definately true. New rules on "block exemption" which came in to force in October 2002
mean that you can have your brand new car serviced and repaired wherever you like. There is more information here:
Originally Posted by DTI
The after-sales market will be opened up, with a change to the rules linking new car sales and servicing. Dealers will still have to ensure that customers' cars are serviced and repaired to manufacturer-approved standards, but they will no longer have to do it themselves; and, independent garages and roadside assistance organisations will have much greater access to technical information, including diagnostic equipment and software.