Got F1's fitted last week. Been back three times to have the wheels balanced,and their machine is reading '0' all the time. However,I'm still getting vibration and steering wheel shake from just before 70mph to over 80mph. Any ideas ? By the way,with regard to F1's. Tons of grip,but I get horrible 'resonance' vibrating through the car on various surfaces now. A real 'howling' sound. Used to get this with the Continentals,on one particular type of surface,but the F1's do it on all sorts of surfaces. Not a big deal,but something to bear in mind for sportback owners considering F1's.