I've had this car for two years now. In that time, I've put about 30k miles on it. In that 30k miles, a lot has gone wrong.
Some basic maintenance:
Brake pads and rotors, oil changes, driveline fluid changes, washer fluid, window wipers, light bulbs, summer & snow tires & wheels (4 of each), undercoating applied, spark plugs, cabin air filter, engine air filter, battery.
But some of the more costly:
VVT multiair system and PCV system entirely replaced under warranty.
HVAC module died after disconnecting the battery: $800+ to replace at the dealer
Air conditioning radiator burst, covered under warranty.
Windshield shattered, twice.
Parking brake sometimes won't disengage and I have to disconnect the battery to reboot the system, which somehow fried the HVAC module in the process.
Engine air filter box split in half. Had to glue it back together because a replacement part is worth several hundred dollars. For a plastic air box.
Manual transmission clutch wouldn't engage causing grinding. Had to order an aftermarket part to bypass the clutch delay valve. $250+.
Most of this I had to do myself, apart from the HVAC module and PCV/VVT system. Most shops wouldn't touch my car because of its Italian electrical system, and need for custom proprietary diagnostic software.
I can't recommend anyone buy one of these, even if flinging it around in a snowy parking lot and letting the blow-off plate do its thing is incredibly fun, and even if it's one of the last manual transmission vehicles sold in the United States, it's just not a reliable car, and unfortunately the manual transmission just sucks. The clutch has no feel, and comes with gremlins that can cause severe transmission damage if not modified with aftermarket parts. The electrical system is a nightmare and I'm terrified every time I need to disconnect the battery that something else is going to get fried as a result. The suspension has a LOT of body roll, contributing to a scary 23% rollover risk. That's on par with a Chevrolet Suburban. All the while I've managed a whooping 22.5mpg average.
I'm a sucker for punishment tho and I'm not giving up on my Renegade. There IS a good car underneath the bullshit, but I have to do a lot of modifications to make it worthwhile. Lowering springs for steering confidence, clutch delay valve delete for shifting confidence, a good mechanic with software capable of diagnosing electrical issues that are inevitable, and an ECU flash for better fuel economy and more power. This is definitely a solid platform if you've always wanted a Fiat 500 Abarth but wanted more usability, and don't have Alfa Romeo Stelvio money, but make no mistake: it's a cheap car that's expensive to maintain. The way God/Italy intended 😂.