I have one 1999 V6 Convertible/Auto with 42K miles and one 2000 V6 Coupe/5SP Stick with 32K miles. I normally get 27+ MPG (HWY) in the 1999 and 29+ MPG (HWY) in the 2000. Both have a K&N Air filter. Other than that they are totally stock and have had routine oil changes and air filter cleaning every 10K miles. Recently the gas mileage in the 1999 has dropped off to the lower 20's. Neither car has had cheep gas. I have done all the normal things to correct this; tire pressures, make sure no brake pads are binding, clean air filter. I had the Auto-Trans fluid recently changed and this did not improve the gas mileage. No computer "error" codes are present. I am at the point where I think I need to replace the spark plugs. I just don't see how platinum plugs can go 100K miles without replacement. There has to be SOME carbon on them. The driver side 3 plugs look easy enough to get to but the passenger side 3 plugs are buried and cannot be accessed from the hood. Does anyone know if the mud skirt needs to be removed from the fender to get access to the passenger side 3 plugs?