Dear JanseyB + Paradigm,
Your points are all noted, and as far as I can see this is going to go round in circles. OP has already stated he has an unclean license, so this could potentially lead to him having to pay a greater amount on insurance alone for the 2.0 mondeo over the 1.6 focus.
Paradigm, I'm glad you can insure an Audi S4 for similar cost to an Audi A1 1.2, you are very lucky. So on your terms why do you have a 4 pot petrol A6? If maintenance and running costs will be so marginal....
In the end it's entirely up to the OP what he chooses. His budget is £2k, if he chooses the focus it could potentially save him ~£500 per year (wild stab at insurance cost for him). So that is 25% of the value of the whole car. Which must be a great deal to consider when you are buying such a cheap car in the first place.
Paradigm's sig obviously shows he's not shy of cash, therefore wanting to save £300 a year clearly doesn't interest him in the slightest. Other people have other priorities, and if the OP buys the focus or the mondeo, then it's his choice and therefore no one can argue, as both are good cars, it's all down to preference. I have merely shown the best car in class, which is slightly cheaper to run than the mondeo which is best car in class.
Thanks