I'm not saying "dont buy a post 2002 car".
As somebody who has owned various ZS's of varying age, I speak from experience when I say the earlier ones as a general rule feel more solid.
For example I have had to replace the fuel tank on our 53 plate due leaking caused by lack of protection I've also had to get some welding done in the usual place just behind the front wheels underneath. Compare that with my 2001 built 180 which has done the same mileage, looks almost as good underneath as the day it left the factory.
The 2001 also has much less wind noise, more solid door handles etc.
As others have said, that doesn't mean all post 2002 cars are falling to bits, likewise it doesn't mean there are no 2001 dogs.
The best thing is to remember that it is a buyers market out there and to try as many different cars as you can. You may not even notice a difference between the different model years and aiming for a 2001 car will reduce your choice somewhat.
If it was me and I wanted a mint mk1, I would bide my time until an early nice low mileage, 1 owner car with full service history comes along. They do pop up every so often and just stand out from the usual dregs which seem to be all over ebay and gumtree these days.
£1500 is the top end of the market for a mk1 so make sure you get a top end car
