This being DriveTribe and me being Italian, of course the best way to "answer" the title is: nothing, the 2011 Fiat Panda is perfect. But not really.
In reality (let's be honest) the Fiat Panda, specially the Second Generation one (2003-2012), like mine, is very much hated, unless you are an Italian mom with a child, or you are a user of DriveTribe, which automatically convert yourself into a lover of the said car (is it?). All jokes aside, about the Fiat Panda the general opinion is very much a "love&hate" + "love it or hate it" vibe. Controversial.
As I (sort of) mentioned before, I love it; but (there is but) there are a few things that really make me furious about that vehicle in particular.
As you are approaching the car to have a blast in it (yes, a blast), it being a 2011 car, thought-of in Europe, you obviously expect it to unlock with the simple push of a button. Not in this case. If you want your 2011 Fiat Panda to unlock pressing a button (as EVERY other car does) you had to spec the top version. Yes, the TOP version to have a normal key fob thing.
Unfortunately the best (or the worse) is yet to come.
Here it is:
If you want to open the boot of the car, as you normally do, from the outside, to, let's suppose, put two shopping bags full of pasta in it, you will find out that the boot doesn't have a thing to open up. This is already a bit annoying but it can be argued that it is something you could expect from this type of car. Unfortunately the topic "boot" gets worse than that.
Let's say that you are a mom, driving your child to school, in this model of Fiat Panda: you will dramatically find out that there is even no way to open the boot from the driving seat (actually neither in any other seat). NO way. You'll have to turn the car off, take the key, and walk to the boot to unlock it, with the actual key.
Every time that I think about this, I genuinely freak out, as I cannot find a decent explanation, nor an excuse. In fact, my mom's old Fiat 600, which had no power steering (I believe) being a 90s Fiat, actually had a mechanic piece of metal near the driving seat that opened the boot from inside, if you pulled it.
But, in any way, in my opinion, all of that only add up to the caracter of the car: being inevitably and very much, a good Italian creation.
P.S. My Panda has more than 100K kms on it and a second owner behind, and has never had any major problems. Soz.
P.P.S. Did you know that the Panda has been the first citycar to reach the basecamp of Eversest (the 5200metres-high one)? That probably says it all.