This is the F20-generation 1 Series range; common diesel choices for 2016 were 116d/118d/120d (and sportier diesels). Most automatics use BMW’s Steptronic unit (often the ZF 8-speed) which prefers regular fluid/servicing; many diesels from this era have DPF/EGR and some later diesels use AdBlue, so confirm whether the car has those systems fitted. Expect pricier dealer parts and servicing compared with mainstream brands, but parts are widely available in Ireland.

• DPF regeneration history and recent long-run usage — look for frequent warning lights or limp-home mode (blocked DPF is common on town-driven diesels).
• Automatic gearbox behaviour and service history — shifts should be smooth with no jolting or hesitation; ask when the transmission fluid/filter was last changed.
• Turbo/intercooler and boost pipe condition — listen for whine, check for blue/black smoke on acceleration and inspect for oil leaks around turbo.
• EGR valve and intake soot — heavy soot build-up can cause rough idling and loss of performance on older diesels.
• Underbody, rear subframe and suspension for corrosion or knocking (10-year-old cars in Ireland often show salt-related wear).