Which used Audi A4 saloon should I buy?
You'll need a good reason not to consider the diesel models. The 2.0-litre TDI engines, with between 118bhp and 168bhp, are the best option - not only for availability, but for running costs and residual values, too. There's also a 2.7-litre with 187bhp and a CVT automatic gearbox and a quattro four-wheel-drive 237bhp 3.0-litre. There is no auto option on the 2.0-litre engines, but the 3.0 is also available with an S-tronic semi-auto gearbox.
The petrol versions start with the excellent 1.8-litre turbo, with between 118bhp and 158bhp, and a 2.0-litre version with 208bhp. Both are available with a CVT automatic gearbox. The four-wheel-drive 261bhp 3.2-litre is more of a car for keen drivers, but is rare on the used market.