Need advice

Hello everybody! I'm planning to buy myself a mk1 jetta. The car that I've found has been kept in a garage for 3 years. The engine is working (diesel) and everything seems to be well, but I just want to ask you what do you need to change or check after a 3-year-long stay in a garage.
Thank you.

tyres and all rubber will start to perish where its sat
check brakes work freely handbrakes tend to get stuck  

Oil, oil filter, brake fluid, coolant, fuel filter, new wiper blades. Drain the old diesel, not sure about that but know petrol has a shelf life and eventually goes off.

As said check the brakes and tyres (quite likely they'll be cracked around the side walls)

rot!

check has not been involved in crime hence the long storage hidden away, bloodstains in the boot good would be a good give away. also get a police check on reg.

love jettas , get it bought. how much he want for it?