This comparo is a nice exercise in mental masturbation but you have to bear in mind how awful the Fiat reliability has been since it has been in the US. This is one of the most problematic unreliable POSes to hit american shores in a long while.
http://www.truedelta.com/Fiat-500/reliability-1014 This is Truedelta's data on the 500.
http://www.autoguide.com/auto-news/2...able-cars.html
In 2015 the 500L has been top of the bottom in many lists of the worst.
The lists go on and on. The 500L has taken the top of the list for least reliable lately, but the 500 has been one of the worst cars (and Mazda in general has been among the best) since Italy took a dump on our shores and left this turd. So maybe first impressions are good and whatever of the latest from Fiat, maybe it's tunable, but it's a POS that will spend a LOT of time in the shop.
There's no comparo. The Fiat will be a problem from day one guaranteed. The Mazda is a known commodity and is by all accounts a great car. Coomon sense should tell anyone who looks further than the shiny sheet metal to AVOID a new Fiat.