What does air filter and coolant have in common when changing the oil?

Has little to do with oil change other than other maintenace items that are needed at times. Check your owners manual to see at what mileage the air filter is reccommended. Unless your car is high mileage the coolant should be ok but level should be checked often. Most shops that do oil changes look at fluid levels, belts, hoses, etc. as a service to customer.