I am going to be doing this within the next week so I can have heat in my winter beater this year. Has anyone ever done this and have any tips? From what I am reading the whole dash needs to come out to replace a $40 heater core F.M.L. I guess the heater cores going was a common problem because of that Dexcool garbage. Would it be wise to do a full coolant system flush before swapping out the clogged unit?