Faults:

Usual maintenance is not exactly cheap. Timing belt, pulley, accessory belt, A/C belt, full-synthetic Castrol motor oil, oil and air filters, water pump - all easily went above EUR 500. I guess it depends on the car service shop, though, for this was the price with the labour included.

Airbag spiral was gone as I bought it... replaced w/labour for EUR 200.

Sunroof control console makes rattling noises @ low revs but I fixed it with silicone glue and now it's perfect.

Left wiper spring tends to weaken with time so it wouldn't make good contact with the windshield. This is valid for all the A6 C4's. Problem is solved temporarily by bending the arm of the wiper a little bit.

Nothing really happened, except they stole my stereo...

Armrest is very badly worn out, actually so worn it's shining.

General Comments:

This is one wonderful hi-speed cruiser. The noise @ 150 km/h is pretty bearable, having in mind it's an inline 4 cylinder 16 valve engine with 140 bhp only. This vehicle tends to stick harder to the tarmac the faster it goes, so it's very easy to lose notion of the actual speed you're going at. There are absolutely no vibrations at 180 km/h. You get highest economy and highest comfort at 130 km/h at gear five. With the air-conditioner on I got 500 kilometres with about 42 litres of 100-octane unleaded gasoline.

This car feels and drives like nothing I've ever driven before. Citroen XM is just as comfier on the straights but the A6 is more stable and has more accurate steering.

Actually there aren't many vehicles that make me feel so safe and comfortable doing chicanes at 120 km/h... There really is nothing like the AWD.

Faults:

Nothing.

Only annoying thing was its appetite for dashboard illuminating bulbs and rear lightbulbs.

General Comments:

Got a car with 98.000 miles, and had it taken away from me 3 years later with more than 200.000 miles on the clock. The only reason the car is no longer with me is the non skillful driving of 16 years old boy-racer, who rammed his uncle's Impreza into my Audi. Needless to say he came off worst.

During 3 years of ownership and more than 100.000 miles, I changed nothing apart from usual serviceable parts (oils, belts, tyres, brakes etc).

The old model A6 was a bit cumbersome and not particularly sharp, but it was amazingly reliable and comfortable car. It was built like a tank, and when I got car taken away from me, all mechanical components were still original, amazingly even all ball joints and tie rod ends were still factory ones (which cannot be said for post 1997 models, which suffer badly from worn ball joints).

My A6 was 2.5 tdi auto with the 140 HP engine, and although not very fast from a standstill, midrange punch was quite impressive. I also took my A6 many times to Europe, and regularly exceeded 120 mph on autobahns in Germany.

Fuel consumption was very good for such a heavy, automatic car with a 2.5 litre engine. Average was around 36-37 mpg. Worst I could do was around 30 mpg. Overall running costs were fairly low due to the fairly reasonable fuel consumption, and the car never needing any parts.

Main dealer parts were fairly expensive, but I only got timing belt and dashboard bulbs from them, and the rest I was buying at independent parts dealers.

My advice would be to buy an old shape A6 2.5 TDI with low or reasonably low mileage (if you can find one) and never sell it. It will easily outlive you. Car manufacturers just don't build cars like this anymore.