Soldato
Unless you drive a minicab, I fail to see the need for an air freshener.
I fart.
Also, living in the countryside you get some awful smells come into the car that seem to like not leaving when you pass a field. Also if you use/abuse the car you'll have people getting in with mud and other smelly things, so it is nice to have a fresh smell.
Mind you, generally the Mondeo smells fine, I only have air fresheners in there because they came with the car and I only found out about them 4months into owning the car. They are in the passenger side sun visor which works quite well, they let off a nice fresh smell every now and then without being overpowering.