I'm looking into buying a used Audi TT coupe and was wondering if it would be better to buy a newer version, for example a '03/'04 with 80-100,000 miles on the clock, or an older car, say '00/'01 thats done 40-50,000 miles?
The most important thing is the condition of the car.
Has is been properly maintained? Does it have full service history? What is the condition of the bodywork and interior? These are much more important factors than age or mileage.
It is likely the '00/'01 car will be in better condition because, although its a couple of years older than the '03/'04 car, it will have suffered roughly half as much wear and tear.