Most 2021 Bayons are fitted with Hyundai’s 1.0‑litre turbo three‑cylinder petrol engine; manuals are common and give better economy and driver control than the automatic. Some examples also have a 48V mild‑hybrid system — that helps fuel use and stop/start smoothness but adds a small electrical component to check. Hyundai parts and dealer support are easy to find in Ireland and the model is generally inexpensive to maintain; note the original 5‑year Hyundai warranty may have expired or be close to expiry on a 2021 car.

• Clutch engagement and pedal feel — test for slip and a clear bite point during hill starts and acceleration (manual transmission).
• Turbo health: listen for unusual whine or lag and watch for blue/black smoke on hard acceleration which can indicate turbo/oil issues.
• If fitted, check 48V mild‑hybrid/stop‑start operation: ensure stop/start works smoothly, no warning lights, and that the battery/charging behaviour is normal.
• Look for corrosion around wheelarches, rear suspension mounts and sills — Irish winters can show salt-related rust on 5‑year‑old cars.
• Unusual engine noises at cold start (rattles from the front of the engine) — listen for timing‑chain/tensioner noise or other knocks while idling and on warmup.