Hello all, i have a few problems with my audi. Its a 1.6 sport with the bgu engine.

The driveshafts are loose vertical play in them about 15mm, i have been told the diff is knackered and need a new gearbox
the engine burns oil was approx 1/2 litre in 500miles
failed mot on emissions before additive was put in (hc high)
rust on front wings, sills and tailgate (audi offered to pay 70% but still a small fortune)

the car has 125,000 on it and full service history not all audi,

Has anyone else come across similar with another car? is the 1/2 litre of oil excessive,

Thanks any help would be welcomed, i maybe looking for a gearbox possibly engine
John