I have zero info on the cooling system history on this car, we were told that it was completely serviced and "ready to go" when we bought it in July of 2012 w/approx. 22,000mi.. As a precaution, I recently planned to do a coolant flush and right about that same time......the low coolant light started to appear. I read for hours about that engine's (4.6L LD8 N*) problems and various quirks. I wanted to believe that it was one of the many leak points like freeze plugs or crossover gaskets. I almost concluded that the dealer that sold us the car, when they did the coolant service, was unaware of the GM sealant tabs and maybe that was all that would be needed to correct a "nuisance" coolant loss. I was shocked when we bought a used 2000 Bonneville SLE in 2003 and I saw a dark, slimy mess in the coolant recovery tank. We were told then that it was from almond shells, etc. , completely normal and GM approved ! I guess it may be the age of the car (and coolant) that's caused the problem and that it's having less than 32,000 miles is not very relevant. It is a nice looking car that has a great exhaust note and is fun to drive, they're also relatively rare so, I guess we'll ultimately fix it and hang on to it. Might even acquire a spare engine as a back-up !