[Fluff time] On a long road trip what would be the worse occurrence to manifest on the trip details inside?

You are on a road trip, more than 100 miles or more from home, which of the following would give you more concern?

• Vehicle overheats in stop-and-go traffic or city driving.
• A rod knock develops (medium, but not the worse)
• A rock/pebble chips the window causing a crack that slowly creeps by the hour across the windshield.
• The oil pressure drops to nothing.
• The gages and radio crap out and stop working.