I also run a MK 4 Fiesta like Dave,
Great little cars, mine is the 1.25 Zetec LX so it has power steering, central locking etc etc
The mk5 isn't much different to the MK4 apart from the bumpers, front lights and some interior peices.
Rear wheel archs can be a problem but if wash it properly then you wont get and problems, mud etc gets up there so when you wash it scrape all the crap out with your fingers....you will be supprised!! same at the bottom of the archs where the drain hole is, clean it out and it'l be fine, mine is 11 years old now and with no rust on the archs at all!!
Front wishbones can be a problem and can last from 6 months or years...just depends how you drive it, dont hit speed bumps to hard etc, they did modify them for the MK5 though, also check that the factory fitted rear metal brake pipes have been changed as this is a comman fault, mine needed doing, the following year Vons need doing and her car is a year younger than nine
rear suspenion on the MK4 is quite soft and can be a paroblem with four up and a boot full, again think this was changes on the MK5
Engines are great...well the 1.25 is, motorway speeds are fine, strange you use less fuel cruising at 80mph than at 70mph, must be something to do with power/weight ratio!! Keep it below 3500rpm and you will save fuel as its at this rpm that the 16v kick in...great if you need a very quick pull off!! iv had mine 7 years, covered around 50000miles and not (fingers crossed) had any problems with it, if it has AC the 1.25 struggles with power when swiched on!!
Interiors are good but rear leg room as a bit of a squash, boot space is good but the triumphs swollow more....
Overall a good everyday car, there comfy, good around town and on motorways, iv had mine for 7 years, von has had hers for about 5 now and there is going strong, you only need to see how many are on the roads today!!
This is mine this year a chester Zoo
Nathan