Lesson learned - Frozen E300 disaster.....
 

So on my way into work this morning it looked as though a fire extinguisher went off under my hood. I thought that I popped a radiator hose so I parked it and went in. Well I pulled it in the shop as it was FREEZING outside only to find the hose intact..... crap. Then I felt the bottom hose, slushy.... double crap. Upon further inspection it looks as though the plastic tanks on the radiator has a small crack. Everything appears to be ok besides that *crosses fingers* so it looks like I will be calling Phil tomorrow and posting in the used parts thread looking for a replacement. Lesson learned: Make sure your 50/50 mix is really 50/50 during Michigan winters.

Anyone else have any near/avoided disaster stories to share?

Actually you should read the side of the antifreeze jugs you use for the maximum freeze protection ratio. Using 50/50 is a good rule of thumb but not the best for freeze protection or maximum cooling.