I live in Glasgow and own a 2002 4motion. Running standard with a green cotton air filter.
Best car i have ever owned. Not the most powerful car on road by a longshot but the haldex 4 wheel drive system makes up for it. It also sounds awesome when pushed....and it doesn't look chavvy.
Doesn't really make sense to own if you are doing a lot of city driving or are a high mileage driver, can be very thirsty. But the fuel consumption aint as bad as some people make out. Car comes into its own on long A roads, especially this time of year.
On a test drive try and wheel spin the car, if you can then the haldex system needs attention.
Rest of problems are the same you will get with most Mk4 golfs...coilpacks, fan unit on the climatronic, Maf sensor etc.
Driven a 1.8T, as well as about 200 other cars, the 4motion is one of my favourites.