Hi guys my S1 is 15 months old now. I am thinking about changing the exhaust as efficiency to dynamic really has no sound difference and I think it should have been louder from the factory. I am obviously still in warranty and also on pcp and when I spoke to the dealer on this I was told it's fine to do so as long as original was put back on at the end of my term which I though was great. Then they said if I need to go in for any warranty work it would also need to be refitted and I'm thinking it's sounds a bit of a pain maybe. Have you guys had any issues with aftermarket exhausts and dealers?