my 172 is 23 mths old done 19000 m and original exhaust has blown. phoned local renault dealer told not covered in warranty wear n tear also told car needs service at 18000 m alredy been 1 A service done. looking at service book it should be 24000m or 4 yrs can anyone enlighten me please. if i put on stainless steel exhaust does this affect the car warranty. anyone had any similar experiences with renault dealers