It's a £600 service as it's tricky to get to the plugs. I would check that has been done or agree it at point of sale. As for the Primacy tyre, there are better tyres out there, though I stuck with the Primacy for the first 25,000 miles and did enjoy it a lot. You can get PS4's if you want grip over anything else. I had more fun though on Yokohama V105's, not quite as much grip but you could play with it more and a good upgrade over the Primacy HP.