The blow-outs were a direct result of me ignoring the fact that the tires were too old (date wise).
Thought I could get one last trip out of them. Wrong answer! First one was about 10 miles from leaving the campsite. Rear axle drivers side - completely shredded the tire by the time another motorist alerted me of the issue. Put on the spare... The next one blew about 50 miles down the road - in the middle of a 4 lane merge with another 4 lane. DW saw that one blow in the mirror. Limped @ 5-10 mph to rest area (3 mi) where I dropped the 5th, and went to a local Tractor Supply (Memorial Day afternoon) and bought 2 tires on rims. Got back home. 2 hr drive became 6 hr... Not the most fun day.
Have now purchased a TPMS system (Tireminder) and getting new tires. Also replacing the original spring hardware with wet bolts/bushings. AND, trying to find new fender skirts for the 2006...