I have the X8 on loan at the moment which as you will now know from playing with it, is the same as the mini's screen wise. I also have the X10 which is mine and to be fair the X8 competes in most areas.
The set up is nice and straight forward, the corners are easily replaced to whatever you want to put there. Bluetooth was a bit of an issue in so far as file transfer but there is an app that gets round it whilst on 1.6 and the 2.1 update I believe has sorted it out. My phones connect quite happily with my Nissan Note so can't see a problem there, the only downside and word of warning is that if you have Bluetooth on all the time it is a battery drainer so you have to remember to switch it on in the phone when you get in the car and connect them again, altho once the initial pairing is done it is only a matter of finding the phone on the radio dial access (assuming the Qashquai is the same or similiar) and selecting connect. I do it out of habit now so not a problem to me.
The battery out of the box on these phones can be a bit rubbish for the first few days but once you have charged/discharged a couple of times they are fine. If your Mum isn't going to be using data then her battery will happily last a couple of days I would think. It is defo 3g use that eats it up. My X8 doesn't have a data package and just casual use and using it to seek answers on the forums it lasts three days plus, connecting via wifi when I need to go online or download apps.
The rest I will leave in the hands of the mini users for a more specific take on the phone.
Hope it helped a bit anyway.