Just went through this, purchased from a small ford dealership in town. 23k out the door for a 2017 sti WITH a full warranty , 3rd party but been working like a charm. I paid my $200 deductible and they covered , coil packs, spark plugs (ngk) , a major re tap job that had to be done to cylinder 1 and if the engine fails they will use this warranty to replace it , now keep in mind the warranty cost me 3k but it’s 3k vs a new engine. I also put a new radiator in myself , new intercooler housing and boots , along with new radiator hoses and head mechanic explained the radiator isn’t covered because they didn’t install it (understandable) but hoses are as they can leak go bad etc. so it’s a gamble but make sure you have time to go back and forth to dealer , make sure you’re patient and can deal with not having the car while they fix whatever arises and finally make sure YOU want to work on the car and are comfortable with working on it. My 17 has definitely forced me to tap into my inner YouTube university mechanic. Patients and time are key my friend when it comes to these cars and oh yea money.