That is a very good point as they often offer low prices as trade in figures and any excuse for them !!!!
Any back from a 100 mile trip and no squeak as yet - that is 3 times as far as the £40 bmw dealer repair. I will keep you updated as and when ' Mr Squeak ' appears again . However I looked this morning inside the exhaust pipe before I put the silencer on and all the silicone spray had evaporated and a fine layer of copper dust remained- ideal.