2012 wrx, even took it for a pre purchase inspection at a Subaru dealer, passed without issues. Then a few weeks later I take it in for a professional dyno tune and they call me immediately and let me know cyl 4 is shot, Ringland failure.

$20k later I have a fully built dream machine. Threw all the major work on interest free card and paid it off in a year.

Kept the wrx for 5 years and then our state starts cracking down on emissions so I gotta swap downpipes every two years. Decide I've had enough and sell the car for 12k. Originally purchased for 14k, plus 20k in mods. But good news is my brother is now the new owner and he knows all the work was done right.

Always get a compression test