This is the B9-generation A4 typically fitted with a 2.0 TDI in manual form; those engines are efficient on long runs but can be sensitive to short-trip use. Diesel-specific items matter here — DPF/EGR issues are the most common complaints on 8‑year‑old examples, and some Euro6 diesels also use an AdBlue system so check that function and refill history. As it's a manual, clutch and dual-mass flywheel wear are items you should expect on higher-mileage cars.

• DPF health and regeneration history — look for warning lights, recent prolonged motorway runs, and heavy smoke on start-up
• Clutch engagement and any vibration (possible dual-mass flywheel wear); test all gears for smooth engagement
• Turbocharger response and noises — lag, whining or grey smoke can indicate turbo or oil-feed issues
• EGR/intake carbon build-up symptoms (rough idle, loss of low-end torque) and related sensor faults
• AdBlue system (if fitted): check injector/level sensor, filler cap and service records for dosing-system faults