I don't know anything about cars, just that low mileage is better.

And that isn't the case!

Well, it isn't necessarily the case. But it could mean that some long-interval maintenance jobs have not been done which a high mileage would have called for - for example. I don't believe traders ask more for low-mileage cars simply because punters think that is better, and no other reason ?

<< But what definitely is the case is that short journeys where an engine and drivetrain doesn't get up to operating temperature is bad for the car. It is also definitely the case that urban running (potholed streets, lots of stopping and starting, sharp turns etc,) is worse for a car than sitting for mile upon mile of smooth motorway or dual carriageway at the legal limit. >>

Quite true. But low mileage (again) doesn't necessarily mean the car has always done short trips. All the 205s I have owned during the last 20 years or so have done between 1000 and 2000 miles a year making occasional (about every 2 weeks) round trips of up to 80 miles. In fact the most recent car has surprised me by averaging 54mpg - the best I have had from a 205 1.4 petrol - by doing most of it at 40 to 60 mph.

I haven't researched the Ford units but regarding the VW group DSG the consensus seems to be the early ones gave some problems but later ones are ok. The wet clutch versions seem to be better ones.

There's even an article on this site about it:

www.honestjohn.co.uk/advice/owning-advice/dsg-gear.../

"As for used vehicles, the same advice applies when considering any used car in that service history and condition is crucial. A post-2012 vehicle equipped with a wet clutch DSG transmission and a full service history should prove to be reliable if the maintenance is continued, but you should think twice about cars with a patchy history or high mileage."