So, Mr Chest has found an honest 2002 model with just over 50K miles. One owner only. It has been used as a daily driver but is still very presentable. Test drive later this morn. It has however started to show a rust scab on both sides of the rear arches where the sill meets the arch, at the arch end of the panel seem. This is common. Can any body enlighten me as to whether this IS the start of something nasty or just superficial that can be totally irradiated by a competent body shop?? This car, in spite of the split & ruined drivers foot well, and surface rust spot on the drivers door step where the plastic step trim has chaffed through paint screams 'Take me home' I must not loose sight of the fact that I am buying a B to drive. Not as a trinket, show piece or an extension. It will be well cared for and D.R.I.V.E.N. Constructive comments welcomed. Ch Ch

Rust in the rear arches is a problem that can be resolved, but that area is so difficult to get too. If you have the skills or some one who is interested in tackling the repair go for it. You say the foot well on the drivers side had a split. I would stick my finger under the rubber mat just to see how damp it is, because rust can be evident on the floor section directly under the speaker, along the inner sill. Looking under the car doesn't always reveal the rust as you it usually this inner sill that rusts.
Hope this helps finding rust is depressing but can be sorted.

Thank you Dave. The test drive was really disappointing. At the first corner I heard fluid behind me. Gave a couple of chaps a bung to use their ramp. (one was a Fiat fan too, the other an Alfa fan! How lucky was I? So we were all reading from the same page) It was not a Barchetta that I was driving, 'twas a barth. The hood compartment was full of water, equally so the drivers foot well. The floor although remarkably sound from underneath, had rusted from the inside of the car to the outside an the drivers side. As the oil started to reach running temp the valves could be heard. (Defective actuator) Cambelt over due, hood slightly ripped.....I need not go on? No. Thought not. Jumped into my trusty Stilo and clocked up a total of 550 miles for the round trip. Two more to see nxt Sat. But, they are both 2005 and more money than I really want to spend. It is with a deep siegh that I wish all interested parties a pleasant week ends driving. Ch Ch

So now you have a better idea of what to look for. Best buying one that is tucked up in a garage over winter, anything that is used as a daily will have issues, especially early examples.
It is with spending more for a good one, or buy a dog for peanuts. Depends on what you want.
Good luck with your search.