Dealers and manufacturers both suck. Waaaay back in the day I was passing a half a mobil home on a grade coming out of Biggs, Oregon. '77 Chevy half ton with 350/350 and 4.11 rear end combo. Snapped a connecting rod during the pass. Brought to the dealer under drive train warranty and was denied due to the opinion I was racing the truck. Their rationale being the optional 4:11 rear end and signs of high revolutions in their inspection. Contacted the manufacturer via phone and registered mail, denied, plead my case again with the dealer, denied. Contacted a lawyer and he suggested the Washington state lemon law, one of the first in the nation. It was arbitrated and I was supposed to pay for half of the short block and the rest was on the dealer and manufacturer. All of a sudden it was discovered that the warranty would indeed cover the repair. I was driving the truck after 3 months of wrangling and eventual repair. It had a slight rod knock when first started on cold mornings. The local Chevy dealer was also the Datsun dealer, I traded it in on a 200sx which ended up having over 400k miles on it before my extended family was done using it. Finally driven to the junkyard when it couldn't pass emissions. Pull a carfax on the Fiat and see if that oil change shows up to bolster your case.