It's been a few years since we were in sons/learning to drive territory so things may have changed. The trouble with the cars you are looking at is they are typical learner/first car choices and that puts the price up. Will insurance be much more expensive if you go up a notch into Focus territory (obviously keeping to the lower power engine options)?

Thank you, useful info. Anything that flags corrosion I’ll discount and look elsewhere.

I doubt the "looking after the pride and joy" factor will make much difference to the sort of significant corrosion threat that the OP is concerned about, since people (and especially old people...er...except me, of course) generally dont do anything about that, though they may AUTOGRIM their sundays away topsides.

On the rare occasion this 'old person' cleans the car, I probably spend more time hosing down the underside than cleaning the rest. I did once polish and wax it in my ten years of ownership.

Don’t overlook the Yaris Mk1 . My DIL s Y reg dating back to 1999 is still going strong and she refuses to replace it . Early ones are Japanese built which is always a plus IMHO and the auto is TQ.

So 26 years of daily use and with routine oil changes every 12 months it’s going to be hard to find a replacement.

Air con , sunroof , CD player all work perfectly . Routine key battery replacement s which she does herself

Nothing much to fear with a looked after Jazz apart from the image thing, Nissan Note is potentially more appealing to the younger driver along with the Swift.

As I’m going to be using the car myself for town trips, small size was a desired quality. Swifts and similar are getting bigger than the Ka’s and Fiat 500’s as they’re superminis rather than city cars, so really getting too big for what I’m after. Bonus with small City cars is a lot are £20/35 tax, which is always helpful.

Swift's have always been bigger than a 500 or (500 based) Ka. But since 2010, Swifts have stayed more or less the same length.

My suggestion, if having as short a car as poss* is that important, would be the Toyota IQ. Being a Toyota, reliability is a given, but unlike the Aygo (and its French cousins) which are just very small cars, some really innovative design solutions (along with a substantial sum of money) were poured into the IQ in order to absolutely maximise the amount of usable interior space possible in such a small car. It is theoretically possible to seat 4 in an IQ, but that requires the driver to not be that tall and/or be willing to compromise their own driving position. Otherwise, best to think of it as being a 3+1 seater!. The dashboard is designed to be as compact as possible on the passenger side which allows the front passenger seat to be mounted further forward that the drivers seat. This in turn allows an adult to sit behind the front passenger in reasonable comfort. It really is a remarkable piece of design and is one of my favourites cars because of this (also more than half a meter shorter than a 500). At your budget, there isn't going to be a huge availability but, being a Toyota, you don't need to worry too much about mileage. Engines are either the Daihatsu sourced 1.0 3 cyl with just under 70bhp or the Toyota 1.33 with just under 100bhp, the latter is the better choice of longer/higher speeds journeys are likely but there won't be as much to choose from.

*And assuming two seats are a compromise too far, otherwise a 2nd gen (all first gen are auto) Smart Fortwo would be the 'shortest' option!

Toyota IQ is a good shout - never sat in one but they do look interesting. Not that many about, but I’m in no rush, so I can have a good look around. Smart four two would also be a fun option - definitely not many manual gearbox models about though - most are the horrible clunky auto - he needs a manual as that is what his test will be taken in.
Being really small isn’t essential, it’s just for my own use I want something that I can park easily in tight multi storey car parks, and not worry about it picking up car park dings from inconsiderate others.