Thanks for your detailed reply, much appreciated!
I saw it was the 'S' spec being the highest spec so was really happy with that! Regarding the points you raised: the pop out windows work, it has 2 keys, central locking works and electric windows work. I will check that the rear wash & wipe, anti fog and clutch pedal position when I get it. What do you mean when you say 'Check the key is the same as the front doors.'? Do you mean the key to open the tailgate?
I have seen a rear tailgate on ebay (see link below), do you think this is upto standard? I will confess I am not a mechanic and don't really know much about cars and engines so it may seem like I ask alot of 'dumb' questions so bear with me! If I used the tailgate below can I swap over the badges from the existing tailgate?
https://www.ebay.co.uk/itm/Tailgate-VW-LUPO-1998-2005-Silver/323750778413?hash=item4b610cd62d:g:1yoAAOSwHf5bATek
I will be getting the service history from before 2013 when I take delivery of the car next weekend so I will see of there is anything regarding the tailgate being fitted in the documentation.
Regarding fitting a new cam belt and water pump what kind of price would I be looking at parts wise? Obv I would add labor costs on top.
The air filter, oil filter, fuel filter and diesel treatment (what is that?) were all done on the last major service in October 2017 where it has only done 3,000 miles since then. There was an interim service which was done in October 2018. Other repairs done since 2013 include: the catalytic, down pipe, CV Boot Kit and wiper linkage and arms done in 2016. New timing belt done in 2015, exhaust gasket in 2014 and finally heater control unit in 2013.
Would the gearbox oil have been done as part of the services?
Finally you say 'disable the EGR system, for cleaner emissions and even better economy', what is EGR?!