Melted pistons!,Bald rear tires,voided warranty just to name a few...FYI it's up to the dealer to void warranty , not Ford .I've warranted many mustang engines that were tuned. Only voided 1 because owner was a a hole and admitted to racing it. Also giving our dealer a bad name on Facebook. I did it just to jack him off. $7200.00 later i got the last laugh!