I have a 2014 Hyundai Elantra and was just told by the dealership i need a coolant flush which i bought into now learning a drain and fill would have been fine. When i got my bill they had a coolant disposal fee which cost more than the flush itself. can anyone confirm this was a scam? the flush cost 109$ the coolant disposal fee was 119$ also on a side note he upgraded my oil change to synthetic at no charge but i was under the impression if you go to synthetic you cannot go back to regular oil....he told me this was wrong. any thoughts on this?