The drivers, at least, end up paying a certain amount of tax in each country they compete in. I would think it's probably the same for the teams. Remember the controversy a while ago about Usain Bolt refusing to race in the UK unless he was given tax exemption?
It's a complex tax World for international sports and you have to wonder if this is part of the reason why Bernie keeps pushing races into the Middle East and Far East as he's able to negotiate preferential tax rates for the teams and drivers.
I presume Toto is trying to put pressure on Lewis to sign an contract extension sooner rather than later. I have a funny feeling if the McLaren Honda partnership looks half decent we will see Hamilton back at Woking before the end of his career.