Gut feeling when you park the car" reminds me of @phoenixa64 picking avocados.

Man that stings, $450 down the drain and no power on top of it. Cracked oil pan is a sneaky one too because it can look fine sitting there in the guy's driveway, then heat it up and it starts weeping. I got a used chainsaw last year that ran great for ten minutes then quit, turned out the piston was scored to hell and the seller had it running rich just to hide it. These days I pop the cap, check every fluid, pull the plug, look at the air filter, all of it before I hand over cash. Sucks that one bad seller makes you side eye every deal after that, but it beats getting burned twice.

Pet checklist should go in your truck, not just your walkthrough notes, since new pets show up anytime.