Hi, Dr. Brian. I live in Tulsa as well, and am the proud owner of a twin-turbo, 2001.5, b5 Audi S4 that I just bought and drove back here from Virginia Beach. It's an awesome car, but apparently it needs a new heater core, among some other things discovered when diagnosing the heater core. Now, these cars have there "quirks" and come with OEM mechanical issues, that once addressed,, makes them very reliable, and amazing cars. I realise that changing out a $37 leaking heater core on a 2001.5 Audi S4 requires the entire dash to essentially be removed and should be about an 8-10 hour job. I've been quoted 15 hours at $96 an hour by the stealership, $865 (including their own heater core cost) by one indie shop in town (should have taken it, but they misdiagnosed the problem as a $515 coolant flush, hose and expansion tank replacement) and then they wanted $865 for the now "leaking heater core" a mere five days later. One shop wants over $1,100 and tells me the car also needs $3,000 of other repairs that I either already own the parts for, and/or are not extremely difficult. It does need new cam seals (common to b5 S4s), which if done properly (i.e. inexpensively and not by "book hours") take 2-4 hours with a tensioner tool and should cost a total of a couple hundred dollars according to all Audi forums. I've been quoted about $1,700 just to replace these damn seals. You seemed to have been clandestinely able to assist the gentleman above with an honest, reliable, local mechanic. If you could also help me out, I would really, really, appreciate it. I simply do not have $1,000s and $1,000s of dollars to spend on a car that I just bought from half a continent away. It is in virtually flawless condition inside and out and was a one-owner car. I need to nip these problems (all of them, if they even exist) in the bud, before they compound, as we all know will happen on any German engineered vehicle, especially a 2001.5 Audi S4. Thank you so much for any advice you may have. I appreciate it!