Simply said, Black on any car looks AWESOME but if you arnt outside polishing and waxing your car every few weeks then dont get a black fiesta. Get a silver one.. in a matter of months a blacky will honestly look shithouse.
The interior is an absolute pain in the backside to keep clean and it does get a little warm inside when parked.
I have found the aircon is great, open windows slightly, turn it on 3 to let hot air out and start cooling down, put windows up and keeo it on 3 for a while, then after a min or so put it on recycled air.
I had 2 other people with me on a near 40 degree day and it was like an esky in my car!!!

but but but air con KILLS power in this car, i find the car is unrefined, jumpy and loses around 40% throttle response and power when its switched on especialy during a hot day.
Definately going to be a better run around car than what you have aswell... and with the savings on petrol you will be buying more from the shops
Good luck with your buy.