The Panda 3 already stray to much from the original Panda philosophy of small, light, useful.
The XL would even be a insult to the Panda name.

Hope Fiat will bring the new small light Topolino ASAP.

Would you buy a Panda XL?

I don't know, but if they called it the:

Giant Panda

Everyone would get one - they could even do a black and white colour scheme!