Took my 87 C4 to Valvoline for auto trans fluid/filter change (66k miles). $100 later I asked to see the old filter. Was told filters were not changed. i asked why and the attendant said "these cars get used to their filter and it can be bad to change them." I emailed VIOC corporate and local rep contacted me and said policy is that they now only flush and refill, not change filters. If you want the filter changed (as it should be) you must go somewhere else or do it yourself.