Just bought a car and got it home and went to change the oil.
Done a routine change, started it up, quickly went into the kitchen to let my wife know I was nearly done and within that 20 second window, oil had burst out of the bottom of the engine and the oil light was on.
I had only had the car for 3 hours.
So tell me, what’s your biggest f*ck up?
Pep Boys sold me the wrong discs for my Ford Taurus back in the mid 2000s. I had both sides fully removed before realizing the replacement discs won’t fit, car was on jack stands, no spare car so had to bother a neighbor to give me a ride back to swap them out. Then they didn’t even have the right part in stock, so we had to go trying other stores, luckily found the right ones at Autozone instead.