Re: The car's saving grace is that it is free as it's my company car & I'm glad to say it's temporary until a more permanent vehicle arrives.
I don't know what company you work for, but a company car certainly isn't free! In fact I am shocked you have a 1999 car as a 'company car' - normally this 'perk' is reserved for brand new cars which you get to keep for at *most* 3 years.
Anything over this and you personally still get taxed with a 'benefit in kind' of 1 third of the brand new cars MRRP each year.
You are being seriously shafted in paying shedloads of unnecessary tax on a car that is probably only worth peanuts (1.4 CL - the lowest spec possible Focus), and clearly has never been looked after or serviced by your company.
I would take this up with the taxman and your boss! You are being shafted.
Comments: "only high 20's to the gallon" & "no grip on wet roundabouts"
You clearly have the very base model car in the focus range, and they are a relatively large car for a 1400cc engine. I'm not sure exactly what kind of performance you were expecting from this engine car combo, but it was never going to be great.
The focus is a great car, and you really need to be realistic of what is possible for a given cost... I doubt any other car of the same size would be better with a 1400cc, or handle better with the base model wheels.