All BMW's and Mini coopers are 4 year life span. would say that is pretty normal life span for coolant...
1997 Honda civic DX( all stock DD)
1972 Toyota FJ40(4" lift, FJ60 axles, FJ60 4speed with split case, 35's, Detroit locker rear, Lockright front, Marlin Highsteer, 105"WB, Saginaw with GM tilt column, soon to have: 30spline longfields, inners/outters, toybox.
1967 Porsche 912(100% stock)